After enduring relentless bullying from a girl named Adagaki Aki in his youth, the overweight Makabe Masamune vows to seek revenge by undergoing a remarkable journey of self-improvement. Transformed into a handsome, accomplished student excelling in both academics and sports, Masamune-kun transfers to Aki's school, unrecognizable to his former tormentor. As he prepares to confront her and carry out his plan for humiliation, Masamune-kun soon discovers whether revenge truly holds the satisfaction he once imagined.