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. 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.

みーくん（染谷将太）とまーちゃん（大政絢）は幼なじみで、10年前の誘拐監禁事件の被害者同士。小学生姉弟の失踪事件と謎の連続殺人事件が同時に起こっている街で、二人は10年ぶりに再会する。いまだにトラウマを抱えていた二人は心をかよわせるが、まーちゃんは乱暴でワガママで、どこか壊れた女の子だった。そんなある日、まーちゃんを主治医の精神科医（鈴木京香）に連れて行ったみーくんのもとに、事件を捜査する刑事が訪ねてくる。どうやら二人は事件の容疑者と疑われているらしい……。