An odd murder case that only targets persons with the family name "Satou" occurs in Japan. Meanwhile, high school student Tsubasa Satou winds up in a parallel world during a fight with a gangster. Everything seems almost the same, but his friends and classmates are somehow different from who they used to be.

Tsubasa Satou can not comprehend what is happening around him, but when he sees a girl getting killed in front of him by a persuer, he finds out that he is now in a world where the Lord of the land plays a fatal game of "tag." The real chasing game that targets people named "Satou."