Ishigami comes home from work and discovers his wife dead. Just then, he receives a phone call from his wife and falls in utter confusion. Suddenly, two strangers claiming to be the police barge in. Ishigami gets accused as a murderer and ends up going on the run. In order to get to the truth, Ishigami goes to his wife’s mother’s house. However, other people have long been residing there with no trace of his wife to be found. Escaping from the strangers after him, Ishigami continues on and struggles to find his wife who had vanished. Along the way, Ishigami starts losing his memory and finds himself acting like someone else. What is his true identity?

ある日、石神武人（西島秀俊）は自宅で殺された妻を発見する。呆然としながら突然鳴った電話に出ると、受話器から聞こえたのは、傍らで冷たくなっているその妻の声だった―。この日を境に彼には別の記憶が混在するようになる。
そして辿り着いた事実、それは―本当の彼は韓国人科学者オ・ジヌだということ。彼の記憶は“上書き”されていたのだ。なぜか彼を捕えようとする警察を騙る男たちから逃れながら、正体不明の女性記者（キム・ヒョジン）と真実を追ううちに、彼は自分の妻を装う女（真木よう子）と出会い― 誰が、何のために記憶を奪ったのか？ なぜ、追われているのか？
―5日後、すべての記憶は消える。