Kotobuki Ringo, a 15-year-old girl, reunites with her childhood companions after eight years since her father's passing. She remains steadfast in her belief that the group includes the person accountable for her father's death. Former students of Ringo's father, the group consists of Shiran, a composed and soft-spoken individual, the strong Kujyaku, the kindhearted Masaki, and the enthusiastic Gogyo, all of whom possess exceptional abilities. Ringo relocates to Shiran's mansion with them, not just to reconnect, but with a tenacious determination to uncover her father's murderer using all means necessary.
