Yuki, Sana & Miko

Yuki is the president of the student council, has a charming personality, and is always willing to help others, but he always keeps its distance when someone wants to talk about his past. Sana is part of the literature club, is easygoing, and is very smart. She keeps as secret that a teacher is her sister. Miko is a shy girl who loves drawing and reading mangas and doujinshis. She is the only daughter of a rich family. Does she have a mistery as the others?