“The person who killed my father...is among these people.”

15-year-old Kotobuki Ringo reunites with childhood friends she hasn’t seen in eight years since her father passed away: the calm and soft-spoken Shiran, the strong Kujyaku, the kind Masaki, and the energetic Gogyo. They were all students of Ringo’s father and all have amazing abilities of their own. Ringo comes to live with them at Shiran’s villa, but she’s not staying with them just to rekindle their friendship... She believes that one of them may be her father’s murderer, and she will stop at nothing to find out who was behind her father’s death.