In a small rural town, a brother and sister goes missing and there's also a serial killer case involving woman as the victims. Mayu Misono (Aya Omasa) is a sophomore high school student in the town. She is called "Ma-chang". When Mayu Misono was young, she was also kidnapped and locked up. Since that time she has been traumatized and has become indifferent to everything around her.One day, in front Mayu's mansion, her childhood friend Mii-kun (Shota Sometani), who was kidnapped with Mayu, suddenly appears. Ma-chang hugs Mii-kun. Up until now, she has waited for Mii-kun. Mayu has lived in the mansion alone, until a week ago, when she kidnapped two elementary school aged kids and has kept them locked in her mansion. To hide Mayu's crime, the four of them will live together in the mansion.Meanwhile, Detective Kamiyashi (Tomoko Tabata) finds out the kidnapping case may be related to the detention case 10 years ago. Kamiyashi contacts psychiatrist Dr. Sakashita (Kyoka Suzuki), who treated Mayu and Mii-kun. Dr. Sakashita believes that if Mayu is treated she may choose to killer herself. By sealing her cruel past away Mayu is able to have balance in her life. To the devastated Mii-kun, Dr. Sakashita told him that Mayu receives happiness by focusing on Mi-kun's world. But there is a big lie there.The detective begins to doubt Mayu as the prime suspect. To protect Mayu, Mii-kun is about to carry out a plan. The truth of what happened 10 years ago becomes slowly revealed. The reason Mi-kun tries to protect Mayu, even puts his life at risk, all connects to an unexpected real criminal.