Saint Liliana High School Second year student. Akiko is Akito's sister, and has a pretty appearance and polite manners. However, she has very serious brother-complex, and is taking a very active way to seduce Akito. She is also very proud of her brother complex and makes no effort of concealing it. She is the secretary of Saint Liliana High School Student Council, but is very reluctant when Akito interacts with other Student Council members.

Spoiler

She doesn't know that Akito has no blood relationship with her and believes that they are twins; according to their deceased mother, Akiko will probably sexually assault her brother once she learns this fact. As for now, believing that they are blood related siblings, and respecting her brother's will is the only barrier that stops her from doing so.

Spoiler

She is a fan of Kouichirou Shindo, and wishes her brother would be as aggressive as the brother in Kouichirou Shindo's novel; however she hasn't notice that Kouichirou Shindo is her brother, and the beginning of Kouichirou Shindo's novel is based on their relationship.