Saya Otonashi

Saya Otonashi (音無小夜, Otonashi Saya) is the main protagonist of the series Blood+ and the one of the daughters of the Chiropteran Mummy as well as the first born. She is a pure blooded Chiropteran queen and Diva's older twin sister as well as Haji's lover.

Appearance
Saya has the small and lithe rosy cheeked appearance of an average ordinary, teenage  high school girl of age 16 with a height of 5'2" (157cm) and weighing 89 lbs (40.4 kg). She is black-haired with different hairstyles throughout time and brown eyes. Back in the zoo, she used to have long hair falling down her waist with the bangs tied behind. She had a pixie haircut by the time of the Russian Revolution. In Okinawa, she likes to keep her bangs and hair again in a pixie cut. After Riku's death, her bangs are shown to have grown past her chin, makeing her hair resemble a bob cut. In the last episode, Kai trims her hair to resemble her Season 1 appearance. She looks very similar to Diva, though Saya is slightly tanner from being out in the sun and has a different hairstyle and eye color and she wears either pink,nude or rose coloured lipstick daily. Her brown eyes change to glowing crimson whenever she feeds on blood, change to chiropteran mode or sense the presence of Diva.

Personality
At the Zoo, Saya is spoiled by the original Joel, and therefore becomes very immature, self-centered, and rude. She herself realizes this as a result of her friendships with Diva and Hagi, which help reveal and nurture her compassion for others. Overall, however, Saya is a bright, cheerful, and innocent person. After she unwittingly releases the vengeful, bloodthirsty Diva upon her foster family and friends and accidentally turns Hagi into her chevalier, coupled with learning the truth about her life and her own inhuman nature, Saya loses her happy demeanor and becomes much more serious and plagued with doubts and guilt. She dedicates her life solely to correcting the mistake she made in releasing Diva by killing her, then forever ending the chiropteran threat by killing herself.

As a result of losing her memories and spending a year in Okinawa as an ordinary girl, with family and friends, Saya develops a sweet and caring albeit somewhat reserved personality. Kai later refers to her as being "a crybaby and a glutton". The latter name suits her as she is much inclined to eating. According to Kaori, no matter how much she eats, she never gets fat. The constant hunger is possibly due to insufficient consumption of blood. At this time, she is troubled by her amnesia, but only becomes increasingly insecure and worried as she learns more about her true identity and experiences more loss because of the chiropterans.

A year after Riku's death, Saya exhibits a much darker and embittered disposition, having fully regained her memories but in the process lost hope, as Moses and Lulu both note. She is unwilling to associate or work with others, particularly Kai and the rest of the Red Shield, not wanting to have to experience losing more loved ones. During the last half of the series, she slowly comes to accept their help.

In the last episode, Saya tries to save Diva after having delivered her a fatal wound. She is persuaded from not killing Diva's daughters or herself, leading to her confession that she does want to live.

Diva
Saya didn't know that Diva was her sister when they first met at the tower. She befriends her and even names her Diva. She frees her to let her sing at Joel's birthday party. After the massacre, Saya hates Diva and vows to kill her. All the rest of the time, she hunts down Diva being ashamed that it was she who let Diva loose. Years later when Saya lost her memories, both Amshel and Solomon tried to make her feel softer towards her sister and give priority to the blood relation. However, Diva's action of draining Riku's blood again awakened her hatred and Saya sticks to the vow of taking vengeance. Nonetheless, after their final battle, it is revealed that Saya still cared for her, holding her sister's crystallizing body and crying as she died.

Hagi
At first, Saya is rude to little Hagi, making him do every small work for her unwillingly. Later she sympathizes and befriends Hagi. They grow up together although Saya never ages. Hagi loves Saya and she also nurtures emotions for him. When Saya loses her senses and even attacks Hagi during Vietnam War, Hagi leaves in despair. In the last episode, Hagi confesses his love for her and they finally kiss to share the emotion. However, they are unable to see each other again until the next time she wakes up.

Kai
Saya treats him as an older brother and care about him alot. Saya is most human around Kai. She responds to his call even when she is in chiropteran mode. It brings her back to senses.

Riku
Saya treats Riku like her own little brother. They have small sibling arguments. When she turns Riku into her chevalier, she accuses herself of giving Riku a cursed life. After Riku's death, she separates herself from everyone so that no one else gets hurt because of her.

George
After the events in Vietnam George was asked to look after Saya while she was in hibernation. He ended up putting her cocoon in the tomb where his family was buried and could only wait until she woke up. When she finally did he decided to raise her as his daughter since she had lost his memory. Even though he knew how dangerous Saya was George always claimed her as his daughter and was reluctant to let her go. During his transformation into a Chiropteran, George asked Saya to mix her blood with his so he could die as her father. With his last words, George asked Saya to keep smiling, confront her past, and look forward to the future.

Kaori
During her time in Okinawa, Saya and Kaori became best friends. Kaori always supported Saya and believed Saya would do great things in the future. Whenever Saya would practice her high jump, Kaori was always there giving her encouragement and urging her to try her best. When Saya returned home for a day, she cried when she finally got to see Kaori. They immediately began gossiping like always, showing that even though Saya had begun to change they were still as close as ever. When Saya left, Kaori was the only one who got to say goodbye, and both girls were left in tears. Later on when questioned by Okamura about Saya, even after being shown pictures of Saya fighting monsters with a sword Kaori immediately rose to her defense and voiced her belief that Saya isn't stupid, that she knows whats she's doing, and that everyone should "stay out of her damn business!".



Skills
Fencing: Saya is trained at the zoo in fencing. She is shown to be agile and quite apt with her sword. This skill comes in handy while killing chiropteran as she wields her katana to do so. However, at the start of the series, Saya has largely forgotten both of these abilities and must relearn how to fight with a sword.

Music: She is also taught to play violin and cello when she was in the zoo. She is an accomplished cello player and even teaches Hagi to play the cello when he was a kid. However, she rarely plays the cello in modern times because of her focus on hunting chiropterans.

Athletics: Saya is a skilled athlete. In Okinawa, she is seen to be very sportive being a remarkable high-jumper.

Exceptional Abilities
Strength: Although not to the extent of Diva's, Saya shows efficient strength in killing the chiropterans and Diva's chevaliers. Kai even calls her "a dragon slayer". But because she chooses not to feed freely on humans and refrains from drinking Hagi's blood as often as she can, her abilities barely matches that of Diva.

Speed: Saya shows herself to be adequately agile.

High Jump: Saya is able to perform high jumps from top of buildings as part of her chiropteran ability.

Telepathy: Saya has heightened senses, being able to sense the presence of chiropterans and Diva. However, she cannot detect chevaliers for some unknown reason. Saya possibly possesses a telepathic connection to Diva and vice-versa. She is able to hear Diva's song when normal humans cannot, could verbally communicate with Diva when the latter did not know how to speak.

Blood Attributes:


 * Healing: Saya, being a chiropteran, has the usual ability to heal herself instantly from any normal injuries. This was first witnessed by Joel the first. As the queen, she has the ability to use her blood to heal others too. But that leads to creating chevaliers. Both Hagi and Riku became her chevaliers being given her blood to heal mortal injuries.


 * Anti-aging: Her special blood stops her growth after aging 16 years. That is why she looks the same even after originally surpassing 173+ years. This applies not only for herself but also for her chevaliers. Time stops for them at the age they imbibe her blood.


 * Producing Chevaliers: An unique ability of the queens. When their blood enters the bloodstream of a human who has lost most of their blood, it revives them in chevalier form, as demonstrated with Hagi and Riku.


 * Possible Power Drainage: After she turns Hagi into her chevalier, she spends only a few years awake from periodically entering a 30-year hibernation cycle, before which she experiences a slow in her regenerative abilities and bouts of fainting spells.


 * Berserker mode: In the first half of the series, Saya sometimes slips into a "berserk" trance in which she becomes much more aggressive and violent, which is mainly how she defeats enemies before she regains her memories. She tends to enter this mode from feeding blood of Hagi. Due to similarities it has led to her frenzy during the Vietnam War. It is possible that this "berserker" trance is a consequence of her being prematurely awakened during the Vietnam War and the subsequent year-long delay in receiving Hagi's blood.


 * Crystallization: When mixed with Diva's blood, Saya's blood crystallize. This is lethal to her. In turn, her blood can crystallize Diva and her blood products. So, Saya uses her blood to crystallize the chiropterans and chevaliers created from Diva's blood. In her final duel with Diva, she plunges her katana loaded with her own blood into Diva who begins to crystallize. Saya is stabbed with her sister's blood soaked sword too. However, due to Diva having lost her blood power, Saya isn't affected.

Power Gain: All queens require daily blood to stay healthy. Saya used to drink human blood in the guise of medicine made by Joel while she was in the Zoo. After waking up at Okinawa, she has regular blood transfusions too. As a queen, the intake of her chevalier's blood probably gives her more nutrition and has impact on her chiropteran power. After drinking his blood, she gains strength to fight as a chiropteran. Hagi's blood caused her untimely awakening and triggered her into berserk mode during Vietnam War. It also helps her regain memories.

Weaponry
Saya's trademark weapon is a special katana with a groove that branches out throughout the blade. Thus, when Saya cuts her thumb on the top edge of the katana, while gripping it so as to draw blood, the specially designed grooves allow her blood to flow into the channel and become distributed throughout the katana. Once loaded with her blood, it is a deadly weapon against Diva and any chiropteran of Diva's bloodline.

After Saya's first blade is broken in a fight with Amshel, David gives her a new one that has a red crystal at the base of its blade, symbolizing her membership in the Red Shield organization. The crystal is a piece of George's body, which crystallized when she killed him with her own blood in order to spare him the fate of turning into a chiropteran.

Chevaliers

 * Hagi (first chevaliers,lover)
 * Riku Miyagusuku (second chevaliers, deceased)
 * Solomon Goldsmith (defected from Diva, deceased)

Birth
In the year 1833, at The Zoo in Bordeaux, France, Joel I and Amshel dissect a chiropteran mummy they called SAYA, which was brought from Iceland, and cut two cocoon-like objects from its body. The cocoons cannot be opened by force but "hatch" once they are bled upon, revealing two seemingly human infants. Intrigued, Joel and Amshel devise a social experiment: they separate the babies and confine they younger infant to a tower to perform tests upon, while Joel names the other Saya after their mummified mother and raises her as if she were a normal human. Thus, Saya is born.

Growing Up
Both Saya and Diva are kept at the "Zoo" by Joel Goldschmidt, where Saya is treated as his daughter and Diva, who is left nameless, is confined to a tower. Saya lives in luxury, like a spoilt princess, given anything she wanted. She learns to fence and play the cello as hobbies. She is routinely given "medicine" (blood) to drink to remain healthy. In the meantime, she is unknowingly being studied by her benefactor (Joel I), who makes notes about her and her sister in his diary and is the first to discover that the sisters' blood crystallize when mixed, which would later become the primary method of killing chiropterans.

In 1863, Saya follows the sound of her sister's song and finds her locked at the top of a tower, but does not realize that they are sisters. Because the other girl does not have a name Saya names her Diva for her amazing ability to sing and Diva also gifts her a blue rose in return. They become friends, with Saya secretly paying visits to Diva and talking to her in the following years. When she learns that Diva wants to get out of the tower, Saya promises to free her.

In 1870, Amshel purchases a twelve-year-old boy named Hagi from his parents. Though Saya believes he is supposed to be her friend, it is actually so that she will mate with Hagi and produce children. Due to her self-centered personality and Hagi's unhappiness at being taken from his family, they are initially antagonistic towards each other. After Saya recognizes his grief and comforts him, they become friends. At around this time, she first teaches him how to play the cello. As years pass Hagi grows to a man and the two soon fall in love.

Saya overhears a conversation Hagi has with Joel in which her father reveals that her "medicine" is actually blood and that she requires it to survive. She also learns that her blood has healing abilities.

Bloody Sunday
On Joel's birthday in 1883, Saya finally finds the key to Diva's tower and releases her so that she can sing for Joel. She leaves to accompany Hagi, who is searching for her, to go find Joel's favorite flower as a birthday present. While Hagi is trying to get the flower, he falls off a cliff and is mortally injured. A horrified Saya tries to help him. Remembering Hagi's earlier conversation with Joel and misunderstanding it, she feeds Hagi some of her own blood, which transforms him into her first chevalier.

Seeking help for Hagi, Saya returns to the Goldschmidt chateau and finds everything engulfed in flames and that Diva has slaughtered everyone, including Joel. Recognizing her mistake in freeing Diva, Saya and Hagi devote themselves to hunting Diva down and exterminating chiropterans, with that mission becoming Saya's only reason for living. They are aided in their goal by the Red Shield, an organization formed by Joel's surviving descendents. As Saya and Hagi embark on the journey to hunt Diva, Saya makes Hagi promise that he'll stay by her side till the end and kill her after she kills all other chiropterans.



After Russian Revolution
During a flashback dream Saya is shown to be hunting Diva in Russia. The incident actually takes place in 1918, after Russian Revolution, when Saya and Hagi are tracking Diva, who is masquerading as Grand Duchess Anastasia Nikolaevna, in Russia. They come to a village and Saya meets a girl called Sonia who becomes much attached to her. It turns out the girl Sonya is actually Grigori, whom Diva has turned into a chevalier. Once they realize the deception, they manage to kill him. But before dying, Grigori manages to stall Saya until Diva escapes with Amshel. Saya manages to crystallize him after Diva flees. After that Saya goes into her deep sleep(30 years hibernation).



The Vietnam War
During a mass bombing on December 25, 1972, Red Shield agents attempt to prematurely awaken Saya when chiropterans are set loose in Vietnam during the Vietnam War, hoping that she will be able to fend them off. So, they use Hagi's blood and inject it in her body. However, their efforts go tragically wrong when she awakes in a frenzy and kills the agents.

Saya hears Diva singing and follows the sound to an empty container which Diva had presumably resided within previously. Now joined by Hagi, she fights Karl (one of Diva's chevaliers) and almost kills him, but he cuts off his crystallizing arm to save himself by preventing it from spreading. Karl flees to a small village. When Hagi tries to stop her, Saya cuts off his arm and slaughters humans and chiropteran alike without distinction, in the process fatally injuring David's father. This rampage is witnessed by both American soldier George Miyagusuku and Akihiro Okamura's father (who takes pictures of Saya's attack).

Once she exhausts herself, Saya finally returns to continue her hibernation. With his men lying dead, David's father, dying, entrusts her safety to George, who stores her in the Miyagusuku crypt when he later moves to Okinawa, Japan.

A New Beginning
Saya's cocoon lies inside the Miyagusuku crypt in Okinawa for years where George has moved with his family after leaving the military. But a sudden accident takes away the lives of all his family members. George visits his family's tombs before trying to suicide but feels heartbeats pulsating from Saya's cocoon as if she's telling him to live on. Newly inspired to live, George starts a new family, adopting Kai and Riku, two orphaned boys and running a restaurant.

In 2004, Saya's hibernating period is over and she awakens. George revisits the crypt and finds Saya crawling out of the cocoon. He almost shoots her before she smiles at him; afterwards, he takes her home and gives her a much-needed haircut and a name to live with: Saya Otonashi. George legally adopts Saya, making her his daughter and Kai and Riku her brothers. And so Saya starts her new life in Okinawa.

Life in Okinawa
In 2005, when Blood+ begins, Saya is an average high school girl living in Okinawa who was adopted a year ago by George Miyagusuku after waking from her hibernation cycle with no memory of her identity or past. Though she appears to be a normal teenager, any injuries she sustains heal almost instantly and she must receive regular blood transfusions to remain healthy. She is watched over by a doctor named Julia Silverstein, who is actually a secret Red Shield operative who monitors Saya's health and amnesia as well as David who pays visit to George regularly reminding him of her duty.

Turning Point
One day, she sees a cello player and hearing him play a music, she falls into a flashback. That night a chiropteran attacks her school and kills a teacher in front of a terrified Saya, who has returned late at night to get back her track shoes. She flees and is followed by both the chiropteran and the cello player, who mysteriously appears to defend and protect her though she doesn't remember him. He force-feeds her his blood, which causes Saya to slay the attacking chiropteran. A shocked Kai's reaction snaps her out of the trance and she faints seeing her own blood-soaked reflection. She is then hospitalized.

After wakening up in the hospital, she leaves her bed, she overhears George and David discussing her purpose as a weapon against chiropterans as she is the only one who can kill them, and runs off. She is later brought back home by Kai after another encounter with Hagi, who will not tell her the truth about her past, telling her she must remember on her own. Later she learns that he is Hagi, her chevalier who vows to help her kill chiropterans.

George takes her to the place where she hibernated and tells her how he found her. Though at first Saya is reluctant to fight and afraid of who she might be, after George is abducted and turned into a chiropteran and she is forced to kill him in order to let him die as a human, she grows resolved to battling chiropterans

In Lycee de Cinque Fleches
To protect her brothers from harm, Saya leaves Kai and Riku behind to infiltrate a Vietnamese boarding school as a student in order to investigate the mysterious hemorrhaging deaths of young black-haired girls (who, incidentally, resemble her), which the Red Shield believes to be the work of a chiropteran. She is accompanied by Hagi, who goes undercover as a gardener for the school. She remains in secret phone communication with David. In the meantime, she becomes fast friends with her roommate Min, who tells her the legend of "the Phantom"; supposedly, the girl he chooses to take away receives a blue rose from him, which Saya herself ends up receiving.

While becoming the center of rumors (for receiving a blue rose from "The Phantom"), Saya continues to conduct nighttime investigation with Hagi in the backyard garden along the bell tower. There she discovers that something like a container is kept in the cellar. She relates her discovery to David secretly and they assume it's Diva's container.

Trip to Hanoi
Saya is attacked twice by the Phantom. A trip to Hanoi brings back memories of Vietnam war where she was slaughtering everyone. She runs in frenzy and finds herself in an alley cornered by the phantom. A fight is underway and Hagi joins Saya halfway through. When the phantom leaves, he is revealed to be Karl, the headmaster of the school and also a chiropteran responsible for the girls' death because of his obsessive fixation on Saya after she fought him in 1972 and cost him his arm, though she does not yet remember him.

The Ball Dance
After borrowing a dress from Min, Saya attends the upcoming annual ball held at the boarding school. It allows Saya to let in her guests: David and Julia. David investigates the whereabouts of the container Saya has mentioned but finds it already moved elsewhere. Meanwhile, at the dance, Saya catches the eye of the most stunning person of the party: Solomon Goldsmith, also Diva's chevalier. He approaches her and asks for a dance and the two of them get along well: neither realizes that they are enemies at first. They are spied upon by a jealous Karl. An interruption from Van makes Solomon leave as he just overhears someone calling his dance partner by the name of "Saya". Later Saya fights Karl as he appears to defend Diva from the Red Shield. During their battle, he figures out that she does not remember him, which saddens him and causes him to leave. Saya, Hagi, and the Red Shield are forced to depart quickly, without Saya getting the opportunity to bid farewell to Min who stands awestruck seeing Saya leave, covered in blood.

Hunting Diva's Container
Elsewhere, Kai and Riku are kidnapped and Saya goes to rescue them as well as find Diva's container. Once the Red Shield tracks down Diva's container, Saya is paralyzed by hearing Diva singing as she begins to awaken, unable to fend off the attacking chiropterans. She eventually reverts to an animalistic mindset and goes on a murderous rampage as she did in 1972, even mortally wounding Clara, another Red Shield agent. It is in this feral state that Saya fights Karl again, who is overjoyed at this shift in her personality. However, she regains control of herself with Kai's help. She once more engages Karl in battle and this time defeats him, though he escapes. She also fails to stop Solomon and Van Argiano from safely escaping with Diva on a helicopter. Although reunited with Hagi, Kai, and Riku, the moment is bittersweet as Saya sadly bears witness to the children who have been permanently altered by Delta-67, including Riku's friend Mui.

On the Railway
Saya and her Red Shield fellows board a train in the Trans-Siberian Railway. There she is met by an imposter who disguises as another fellow agent, Elizabeth. A chiropteran attack on the train knocks out Saya unconscious. She remembers the time she and Hagi visited Russia and the incident of Grigory. When she regains consciousness, she meets Liza and Riku. Later, Liza is revealed to be a chiropteran who refers Saya to go to the Zoo where all her memories begin.

Trip to the Zoo
Saya and Hagi journey to the Zoo in Bordeaux. They get attacked by the Schiff on the way there. But they manage to reach the zoo. As soon as she crosses the gates, she finds the place familiar. The fountain at middle, the steps remind her of older times and she slowly remember parts of her memory. She lived in the mansion over a hundred year ago, in the time of Joel I. Her growing up, meeting Hagi and everything else started there. While Saya is lost in the memories of past, Solomon appears. Hagi tries to fight him off but Saya agrees to listen to Solomon. He conveys her his part of story and wants her to leave humans to join her original family: her sister Diva! At this, Saya is shocked to learn that it is her own sister that she is after. Solomon tries to gain her confidence but Hagi interrupts. As they fight, a voice strikes Saya and she follows it as fast as she can to find herself in the tower, face-to-face with her sister Diva who has been drinking Riku's blood. Saya gets enraged and accepts the fact that Diva although being her sister, is dangerous and has to be got rid of. She fights with Diva whose inhuman strength soon overpowers her. When the battle ends in an undecided way, Saya returns to her unconscious brother. Kai pleads Saya to save Riku with her blood. Knowing what it'll turn him into, Saya is forced to accept the consequences after feeding Riku her blood.

Destruction of Red Shield HQ
A turmoil of emotions follow as Saya faces a distant Kai and self-accusation of turning Riku into her chevalier. Solomon's tip warns them to relocate into the Headquarters to avoid sudden attack. However, an unpredictable Diva comes with Karl on board the ship in search of Riku. Saya tries to fend her off but Karl stalls her. She is too late to save Riku who is once again victim to Diva and this time, raped and dead. Meanwhile, the Red Shield hierarchy decides to destroy the HQ to bury Diva with it. So, Saya remains with Hagi to hold down Diva and Karl while the others leave. But the fugitives flee before the ship is destroyed.

Chasing Diva
After Riku's death, Saya disappears for a year, along with Hagi. When she returns, she has longer hair and a harder, darker appearance. Now accepting of her chiropteran biology, she accepts the necessity of feeding on Hagi's blood to live and be strong enough to fight. However, she has a less cheerful personality, is more morose and less talkative than she used to be. Moses and Lulu both remark that she has lost hope. Believing the fight with Diva is hers alone, and not wanting to have to grieve for any more lost comrades, she avoids cooperating with Kai or the Red Shield. Saya's friends repeatedly work to help her understand that this fight is not for her to bear by herself, and that she is never alone, eventually succeeding. As the battle with Diva continues, Saya's next hibernation period draws nearer, she starts having sudden bouts of fainting spells, and her regeneration ability slows.

The Final Duel
At the Metropolitan Opera House, Saya confronts Diva in a final duel, which ends as they simultaneously pierce each other with their blood-coated swords. Saya is unaffected by Diva's blood, because it lost its potency when she became pregnant. Diva, however, begins to crystallize, and Saya cries for her and tries to hold her shattering pieces together.

Facing the Truth
With Diva dead, Saya turns to kill the babies and herself fearing that if they lived, they would be forced to become military weapons. Kai pleads with her to live, promising to protect her and the babies and make anyone afraid of her understand. He smacks Hagi back to his senses in order to stop Saya. Hagi disobeys Saya for the only time in his life, taking her sword and confessing he has loved her from the moment they met. Saya tearfully admits she wishes to live as she kisses Hagi and says she wants to live with him, Kai, and everyone else.

Departure
The news of possible bombing reaches them. She and Kai escape the opera house with the babies in tow as Hagi battles a returned Amshel and the US military begins bombing the building. Before the bombing happen Hagi had asks Kai to protect Saya and give her a place to be happy, hearing this made Saya panic and Hagi then smiles like in the past and says nankurunaisa and says, "I will always love you Saya.", before the building started to collapses on him. Seeing this made Saya burst into tears as she screams his name in believing that he is dead.

Returning Home
A month later, back in Okinawa, Saya finally goes into her next thirty-year hibernation period. At her request, Kai puts her back in the Miyagusuku family crypt to sleep, and he watches over her while raising Diva's Children.

Epilogue
Several years later, Kai and the children visit Saya in crypt. There a fresh pink rose with Hagi's blue ribbon is found, which proves to Kai that he is alive and waiting patiently for his love to wake up from her 30 year long hibernation.

Blood+ manga
Saya lives in Okinawa with George, Kai and Riku. Suffering from amnesia and getting regular transfusions in the form of check-up, she faces quite a trauma with her abnormalities. After the first chiropteran attack, she is reunited with Hagi and shown by David that she is anything but normal - shooting her a bullet to show her instant healing capability. Meanwhile, Charles picks up her trace. He stages a blood scene during the high school festival to awaken her so that they could fight.

Blood+: Adagio
Saya wakes up from her first hibernation period in 1915, much to the relief of Hagi and the Red Shield members, who had been puzzled and disturbed by her extended sleep; as she slept, the Red Shield had also discussed whether or not she would become like Diva and how they would kill her in that scenario. In a conference with Red Shield agents, she receives a specially-designed sword and learns that the only way to kill chiroptera of Diva's lineage is to poison them with her blood. She expresses frustration that she must fight chiroptera to Hagi.

In 1916, Saya and Hagi arrive in Petrograd, Russia to track down Diva, who is masquerading as Tsarevna Anastasia Nikolaevna. They join the Imperial Orchestra to investigate; humorously, Saya's demonstration at playing the cello causes her to be ranked as a novice whereas Hagi, whom she taught in the first place, is immediately accepted.

Saya feels extremely guilty when she slays a new friend of hers named Claudia out of the belief that she is a chiropteran: as a result, Saya has an argument with Hagi. Hagi leaves for the time being and attempts to kill chiropterans himself to relieve Saya from her burden. This gives Diva's new chevalier Grigori the opportunity to capture him and try to convert Hagi to his side but end in failure. It also makes Saya botch her attempt to kill Kiska, who has been transformed into Diva's chevalier.

It is revealed by Red Shield agents David and Roman that the letter Saya received that had given her the order to kill Claudia did not actually come from the Red Shield (presumably, it came from Amshel or Grigori). When she, David, and Roman investigate Claudia's home, they find that she is slowly transforming into a chiropteran and Saya is forced to kill her permanently in front of Claudia's brother Vincent; though she suceeds, Roman is killed in the process.

Saya reunites with Hagi and apologizes for losing her temper with him earlier, though she feels that she is too easily forgiven by Hagi. In the meantime, Grigori is discarded by Diva and replaced by the Tsarevich Alexei as her chevalier. Desperate, he seeks Saya out and begs to be her chevalier.

Saya and Hagi go to the Imperial Orchestra to search for Diva; there, Victor, a member of the orchestra and also of Grigori's cult that seeks to gain immortality by the blood of a chiropteran queen, cuts Saya and drinks her blood despite her frantic warnings, but dies instead. Hearing Diva's song, Saya tries to follow the sound but is intercepted by humans who turned into chiroptera and must slay them. Upon seeing all the death surrounding her, Saya requests a shocked Hagi to kill her after she kills Diva. Saya and Hagi then fight a newly-transformed Alexei, and she kills him in a fit of rage when he tells her that she deserves to die for wanting to kill Diva. With Diva and Amshel having escaped in the meantime and Grigori washed away by the river, Saya and Hagi leave Russia together, reconciled.

Trivia

 * Despite major dissimilarities in the two series, the original Saya of BLOOD: The Last Vampire and the Saya of Blood+ anime do share some similarities (most likely as homages to the former):
 * Both work for or ally with the Red Shield, and have "handlers" in the form of David and Lewis.
 * Both call for their sword from an ally (Blood+'s Saya from Hagi, The Last Vampire's Saya from David).
 * Both infiltrated a school as a student to hunt for chiropterans.
 * Both break their swords during a fight.
 * Both are the same species as the chiropterans they hunt, but are "pure" versions of such.
 * Both were raised as experiments.
 * Both were alive during the 19th century and were photographed during this time.
 * Both have twin sisters who lack their regard for humanity (Blood+'s Diva, The Last Vampire's Maya).
 * During the last half of the series, Blood+'s Saya exhibits a somewhat similar personality as The Last Vampire's Saya.
 * In Japanese, saya means "scabbard" (i.e. the sheath of a sword) or "shell" (such as the shell of a pea). Both meanings are relevant, as Saya is an accomplished swordswoman and she was born from and hibernates within a cocoon (a shell). Likewise, otonashii means "obedient" or "quiet", suiting her reserved nature. It should be noted that saya also means "evening" when written with the Kanji meaning "small" and "night." This translation can also be pronounced as sayo, as Akihiro notes in the anime.
 * Ironically, Kai considers himself Saya's older brother even though she is over one hundred years older than he is.
 * Although Saya and Diva are twins and hatched from their cocoons at the same time, Saya is dubbed the "older" sister and Diva the "younger" because of their personalities (Saya is serious and Diva is immature).
 * Saya's decision to crop her hair short has never been explained in-series but was featured in two different mediums:
 * In the manga adaption of Blood+, she cuts her hair after Diva slaughters the patrons of Joel's birthday party. As she does so, she thanks Hagi for having called her "beautiful" before.
 * In Blood+: Adagio, she has a nightmare in 1915 (over thirty years later) that flashes back to Diva slaughtering people at the Goldschmidt estate and calling her "sister". When she wakes up, she mistakes her reflection for Diva and messily chops her hair off to better differentiate each other. Realizing how badly she butchered her hair, she then sheepishly asks Hagi (who had walked in on her) to "fix it".
 * Saya's gluttony could be because of her reluctance to drink blood freely; because she feeds rarely, she burns through calories more quickly and must consume a great deal of human food to supplant her natural diet.
 * Saya is associated with pink roses.
 * Saya's personality while living at the Zoo is reminiscent of Diva's modern-day personality.
 * Although Saya was the one who first taught Hagi to play the cello, she is rarely seen playing one. In Blood+: Adagio, she plays, but badly, judging from the reactions of other characters.
 * Although usually referred as 'Saya', she is sometimes called 'Otonashi' by Mao (Which is an inconsistency).
 * Both Riku and Diva (the younger siblings) died. In contrast, both Kai and Saya (the older siblings) survived.
 * Saya's short haircut is donned by Kanade and Hibiki in the epilogue.
 * Although she presumably has a chiropteran form (judging from the remains of her mother), Saya never transforms, either due to preference to remain in human form or inability to transform altogether due to her sparse feeding on blood.
 * Despite Saya and Diva being twins, there are a few differences between the sisters. Saya's eyes are red, Diva's are blue. Saya has tanner skin due to being allowed to walk about in the sun, while Diva has a paler complexion, as she was locked up in the tower by Joel I.  However, their nationalities, facial features, and heights are exactly the same.

Memorable Dialogue
[Saya is going to kill Diva's children]
 * Kai Miyagusuku: What do you mean you're going to die?
 * Saya Otonashi: We'll surely be used again as weapons of war. I don't want to see another war over our blood. I don't want to see anyone get hurt anymore.
 * [to the babies, raising her sword]
 * Saya Otonashi: I'm sorry.
 * Kai Miyagusuku: Stop it, Saya!
 * Saya Otonashi: We must not live on!
 * Kai Miyagusuku: Don't be stupid! Who decided that? If there's anyone saying you shouldn't exist, I'll kick his ass! And I'll make him understand you're just a normal girl; a crybaby and a gluten!
 * [Hagi blocks Kai from getting any closer to Saya]
 * Kai Miyagusuku: I'll look after you. One way or another I'll find the place where you belong. So just stay with me. Don't you think so too, Hagi?
 * Hagi: I am a servant of Saya. I will do as she wishes.
 * [Kai punches him]
 * Saya Otonashi: Kai!
 * Kai Miyagusuku: Who are you? Be yourself! Just say it in your own words: What do you want? Even you, don't you love Saya?
 * [pause. Hagi turns to Saya]
 * Hagi: I wanted to see your smile. Once more, like when we first met. I have been serving you and was glad to return to you, even if I had to give everything up. When I first awakened after becoming a Chevalier the first things you showed me were your tears. And, driven by rage, you chose to take up arms and fight. However, when I found you in Okinawa, you were wrapped in happiness. There was the smile I could not give you, no matter how much I wished to. It was you and your family, Kai, who gave that smile to her.
 * [he moves and kneels down with her]
 * Hagi: Saya, as your Chevalier I have been living according to your wishes. But now, I must go against your wishes, just this once.
 * [he gently takes away her sword]
 * Hagi: Live. Please Live.
 * Saya Otonashi: Hagi...
 * Hagi: Live today for tomorrow. You do not need to fight anymore.
 * [he kisses her check, and she is silent a moment]
 * Saya Otonashi: I want to live!
 * [they kiss, then he cradles her in his arms]
 * Saya Otonashi: I want to live together with Kai, Hagi, and everyone else! I want to live together with everyone!
 * [the babies giggle]
 * Kai Miyagusuku: They're saying they want to live too.
 * Hagi: From now on, you can live the way you want. Live today, and smile tomorrow. If you live life to the fullest, looking forward to tomorrow, things will work out. Nankurunaisa!

Saya's Wardrobe
Saya is shown in a wide range of clothing throughout Blood+. Following is the list of her clothing:
 * 1) She wears a soft white dress of medium length during Vietnam War. Used in: Episode 1, Episode 10-11, Episode 30
 * 2) Her gym clothes consist of a white top with blue shorts. Used in: Episode 1
 * 3) School Uniform (spring): It is a white shirt with red bow and black knee-skirt. Used in: Episode 1- 7, Episode 50
 * 4) School Uniform (winter): The same as spring with an addition of black jacket and grey socks.
 * 5) Casual Pink shirt and brown pants
 * 6) Pink top with khaki short jacket and white knee length skirt
 * 7) Powder blue turtleneck top with same jacket and skirt
 * 8) Yellow sleeveless turtleneck top (worn beneath the dark red coat) with the same skirt
 * 9) She has pink pajamas. During her stay at Glay's farmhouse, she wears borrowed pajamas which are lilac in color
 * 10) Vietnamese Dress: The Vietnam School Uniform she wears a traditanal vietnamese lilac colored ao dai robe and white trousers along with purple flats. Used in: Episode 8 - 11
 * 11) The nightgown Saya wears during her stay in Vietnam is white with pink bands
 * 12) Saya is given a pink party dress by Min to wear on the ball night at Lycee. The dress slips a little down her shoulders and hangs to knee level. She couples it up with pink strap heels and a pink choker with pearl earings and a pearl bracelate.
 * 13) At the Vietnam jungle, Saya wears a safari outfit with pink inner tops and black short shorts.
 * 14) While journeying on the trans-Siberian railway, Saya wears a red and white winter coat with brown boots. She also has a pink turtleneck top beneath the coat she also wears a short khaki skirt which falls to her upper thighs and thick black pantyhose.
 * 15) In the Russia flashback Saya wears red and black winter coat with a Russian style hat. Used in:Episode 17
 * 16) 1880's Gown: It is a pink and white gown
 * 17) Fencing Attire: Saya wears a white fencing suit with brown belt
 * 18) Hibernating Gown: This dress is of a beautiful soft pink shade with large white frills
 * 19) Travel Gown: It is a red and white gown accompanied with a red hat
 * 20) Purple Leather Coat: Saya wears this purple leather coat throughout the last half of season three and most of season four. She also wears a pair of same colored boots with the coat. Used in: Episode 33 - 38, Episode 42, Episode 44 - 46
 * 21) The White Gown: It is a gift from Solomon. It is a simple yet elegant white gown with petal shaped design forming the waistline and lower cut
 * 22) The Opera Dress: It is a pink sleeveless gown with purple inner top and pink scarf. Saya buys this when she goes shopping with Kai. She wears this outfit for the final duel with Diva. She rips through its lower half for the ease of her battle.
 * 23) Omoro Waitress: It is an addition of a pink apron to the spring school uniform.