Riku Miyagusuku (宮城 リク Miyagusuku Riku) is the adopted brother of Kai and Saya, the youngest of George Miyagusuku's three adopted children and Saya's second chevalier.
Story[]
Life in Okinawa
Riku leads a normal, cheerful life in Okinawa with his adopted father, brother and adopted sister. After their father's death, he accompanies Saya on her journey to slay chiropterans.
In Vietnam
Riku accompanies his brother and sister to Vietnam. With Saya gone to the Lycee, he finds himself passing time with Kai. He wanders around in the neighborhood, meets other children, plays with them. There he meets a girl around his age called Mui who can also hear chiropterans like he does. He and Kai save her once, stay in the orphanage where she stays and get kidnapped. After they break out of the prison and reunite with Saya, Riku's friend transforms and is taken away.
At the Zoo
Riku goes to the Zoo with the other Red Shield members. He is left alone as others spread out to search for Saya. Then he hears Diva singing and getting drawn by the voice, he soon reaches the tower where Diva was imprisoned long ago. When he reaches the dark cell, he sees a girl and mistakes her for Saya. As soon as Diva's eyes glow bright blue, he realizes that she's someone else. But he is too late to escape Diva who starts draining his blood as he lets out a scream.
Becoming a Chevalier
After Diva drinks most of his blood at the "Zoo", Saya is forced to turn Riku into a chevalier to save his life. Afterwards, Riku shows a compulsion similar to Hagi's to protect Saya at any cost. Despite a brief estrangement, Riku remains close to his older brother Kai and works to heal the broken relationship between Kai and Saya after Kai learns the truth about her.
Rape and Death
Draining Riku's blood seems to cause Diva to develop a strong interest in him. She takes Karl to the Red Shield Headquarter to find Riku. Once she finds him, she raped him then kills him with her blood. In the light novel adaptation, it's explained that something in Diva's eyes causes the Chevalier blood in Riku to react with a "maddening desire" that causes him to be incapable of escaping or physically resisting Diva's actions. After Riku's death, Kai has a piece of his crystallized body made into a pendant, which he wears around his neck to remember his lost brother. As a result of her attack on Riku, Diva becomes pregnant with his children. His twin daughters are birth posthumously a year after his death and Kai, out of love for his late brother, raises the children as his own
Story Of Joining Sora's Team[]
Beatrice hears Riku die she feels sad because he is like Kanon in young brother , She goes with Kanon to the Diva's place from Sora tell information to him for take it Riku corpse , she is and Kanon did it steals Riku's corpse from Diva and Diva servant's then She is resurrects Riku and hides her real body after running away he thanks her, Beatrice turns out to be not what she thought, he was also given powers Beatrice's endless awakening for his training with the others child and Beatrice becoming his Teacher with Virgilia.