Akito is quite protective of Akiko, and people around him often comment that Akito has a serious sister complex, although he insists that he only sees her as his little sister. He has secretly made a living by writing erotic novels of brother-sister incest under the pen name "Kōichirō Shindo", which are very popular since before the siblings started living together. He uses his relationship with his sister as an inspiration for his novels, with the characters' names being very similar to their own.