Mui

Mui is a young handicapped Vietnamese girl who becomes Riku's friend when they meet in Vietnam during Saya's investigation there.

Appearance
Mui has tanned complexion and brown hair tied in two side ponytails. She lost her left leg to an exploded bomb and uses a single crutch to walk. She wears a cheerful smile with a friendly air.

Personality
Mui is shown to be a very friendly girl. Although she has to struggle for survival, she stays cheerful.

Skills
Mui can play the piano. She was going to a music conservatory in France courtesy of the pharmaceutical company, but she has abandoned the idea because of her family.

Anime Plot
Riku gets acquainted with Mui when Saya goes to Vietnam to investigate about the Phantom for leads to Delta-67 project. Riku and Kai go back to Mui’s orphanage-type home with the other kids and stay there for the night. They learn that a certain pharmaceutical company is supporting the home, and that Mui is even getting medicine regularly from a man in a suit.

Riku is shy at first about Mui not having a leg but later overcomes it and become friends with her.

Riku finds Mui on the streets looking at a metal detector, which she wants to buy. Riku buys it for her, and gives her the money in his pocket before sending her off in a taxi towards her home. In the end though, Kai and Riku chase after her after Riku learns that the metal detector is used to find land mines. Luckily, they find her safe and sound in her village.

The two stay there for the night, but Riku and Mui hears a certain sound. When they go outside to investigate, they’re kidnapped by a group of men led by the man from the pharmaceutical company. Kai, who was captured along with Riku and Mui, escapes from their prison and frees his brother. But with the container of Diva open, the boys are surrounded by a bunch of red-hooded children who are attracted to her singing. Saya arrives the scene and Riku is comforting a scared Mui, who is developing cracks in her skin. Kai finds them, but after seeing Mui, he pushes her away. Riku protects her and claims there’s nothing wrong with her. Mui and the other children seem to have transformed into Chiropterans and hold the two boys down, ready to eat them. They pause when Saya gets up. In the aftermath, Mui and the other children are put in cages, and the group is hopeful that they can return them to their previous form.

Blood+ Manga
Mui is shown in Chapter 2 of Blood+ manga. When Saya and others arrive in Hanoi, Vietnam with a clue of blue rose to search for Riku who has been kidnapped by Charles, Saya sees Mui with a basket full of blue roses. They meet there and learns from Mui that the roses are marketed by  a medical company that funds their village. Mui takes them in her village which happens to be the one Saya massacred in Vietnam War. Mui and Saya become good friends. She even lends Saya her vietnamese dress to wear. Mui overhears the village people talking about handing Saya over to Cinq Fleches people who'd give them all facilities in return. They talk about trying to kill Saya too. So, Mui takes Saya and tries to run away from the village. They are chased by chiropterans and Hagi saves both of them. But Mui suddenly transforms into a chiropteran hearing 'the song'. Altough Saya doesn't want to hurt her, she beheads Mui once she realizes that is the fate for the humans who turn into chiropteran and that she is the only one who can save them from that state by killing them.