Takemichi Hanagaki is a useless part-timer who has hit rock bottom in his life. He learns that Hinata Tachibana, the love of his life who he'd gone out with in junior high school, has been killed by the 'Tokyo Manji Gang', the worst, most evil gang of villains in the world.
The day after learning of the incident, Takemichi finds himself on the train station platform when someone pushes him and he falls onto the tracks, ready to die- but then he opens his eyes, and somehow finds himself having time travelled 12 years in the past.
Having time travelled to the peak of his life 12 years ago in junior high school, in order to save his girlfriend and change the self he has been running away from, he begins his life's revenge!