Diva's Children

Diva and Riku have twin daughters who are later raised by Kai. They are named Kanade Miyagusuku and Hibiki Miyagusuku.

Appearance
The two baby girls have the same countenance except their eye color. Kanade has blue eyes while Hibiki has brown. When shown with Kai at the epilogue of the anime, they are seen to have pixie cuts like their aunt Saya.

Plot
Diva's children were conceived when Diva raped Riku at the Red Shield's HQ. After a year of Diva's being pregnant with them, they were cut out of her stomach by Amshel as two cocoons-type objects similar to those Saya and Diva were first found in.

Diva cared greatly for her children before they were even born, because she wanted to have a family more than anything else; in her dream scenes with her children, she was depicted gently stroking the cocoons and singing to them.

The children finally hatch at the time of Diva's death, revealing that they are female twins who bear a great resemblance to Saya and Diva. Having killed Diva, Saya prepares to kill them and herself, but is persuaded by Kai and Hagi not to. Amshel recovers and tries to take Diva's children to replace the loss of their mother, but Saya and Kai protect them, escaping while Hagi holds Amshel off long enough for both to apparently perish in the collapsing building.

Five years later, Diva's children visit Saya during her hibernation; as per his promise to Saya, Kai raises them like they were his own children, even trying to get them to call him "Dad".

Personality
Both of the baby girls are shown to be sprightly and cheerful being raised by Kai who has kept them away from the bloody history of their ancestral lines. They are quite cheeky as they keep on teasing Kai, not calling him "Dad".

Trivia

 * Kanade means "performance" while Hibiki means "echo/ sound". This could be a reference to the names of the previous Queens as Diva was a performer and Saya's surname Otonashi means "silent".
 * The twin girls do not exist in the manga.
 * They have a vital role in the anime since Diva's blood lost powers due to conceiving them.
 * They seem to have Saya's hair style as seen in the epilogue.