The story follows Karen Yuzuriha, a 15-year-old girl who transfers to a new school in Tokyo after her father's job relocation. Karen is a bit of an airhead and has a hard time making friends. One day, while exploring the school's rooftop, she meets a mysterious boy named Hijiri Kujo, who seems to have a dark and troubled past.
As Karen navigates her new life in Tokyo, she discovers a mysterious app called "The Case Board" which allows users to share and solve cases. She becomes obsessed with finding clues about her father's disappearance and starts to investigate. karen yuzuriha eng sub