Kyoshiro is instantly likened by Kū to the prince in her dreams when he transfers to Kū's school from the legendary Jōtō Academy. He is a refined gentleman, adept in horseback riding, and has a tendency to play the violin while deep in thought. Kyoshiro is the youngest of the four children in his family. He supports the Central Student Government and has also stated his intention to recover and destroy all of the Absolute Angels, following what he believes to be the wishes of his deceased brother, Kazuya. He eventually falls in love with Kū, which forces him to re-evaluate his belief about Absolute Angels and the way he has been treating Setsuna. He later confesses his love to Kū, only for Setsuna to overhear and burst into tears, and, albeit after some time, Setsuna understands and only agrees to Kyoshiro's plans after she accompanies him to find Ku and says her farewells.