One day, the 26-year-old unsuccessful Hanagaki Takeshi learned on TV that his ex-girlfriend Tachibana Hinata from junior high school was involved in a conflict and died for no reason. The next day, he was pushed off the platform while waiting for the train. Just when he thought he was dead, he came to his senses and found that he was reborn in junior high school 12 years ago. Takeshi found Hinata's younger brother, Naoto, in this era, told him what happened 12 years later, and asked him to protect Hinata. After the two shook hands, he returned to the modern era again, but found that a more unfortunate future was waiting for him... This time he needs to travel again and declare war on his once cowardly self, desperately changing the fate of himself and his lover!