Yoriko Kusumoto is a scatterbrained schoolgirl whose affections are solely focused on Kanako Yuzuki. The plans for their summer trip abruptly come to an end when Kanako is found severely injured on train tracks and Yoriko in tears on the platform. Shuutarou Kiba, a detective on the train, takes on the investigation, only to uncover a web of deceit involving the Yuzuki family, particularly Youko Yuzuki, a renowned actress and Kanako's sister. Despite surviving the surgery, Kanako's unstable condition prompts Youko to entrust her care to Dr. Koushirou Mimasaka at a foreboding, box-shaped facility deep in the woods. During a visit by Kiba and Yoriko, Kanako disappears without a trace. Kiba's burden increases as he uncovers more horrifying discoveries, including the discovery of young girls' limbs in boxes. Kiba is informed by a colleague that the gruesome findings are likely linked not only to Kanako's vanishing but also to the truth behind her sister. With the aid of colleagues Tatsumi Sekiguchi and Akihiko Chuuzenji, Kiba must navigate this series of crimes to locate Kanako and uncover the truth.