No matter how hard he tries, Aihara Takuya is just a weakling. Not only the boys, but the girls pick on him too! His step sister, Natsumi, the president of his school's chemistry club, Mami, and even his childhood friend, Asuka, they all enjoy teasing him. Just when he thinks his life couldn't get any worse, he spills some vials of chemicals while cleaning up his school's chemistry room, splashing some onto his body as well. He looks down to assess the mess, and finds a new pair of breasts sticking out of his chest! He grabs them in disbelief, and discovers that he's been transformed into a girl! And so begins Takuya's hilarious erotic adventure to search for a cure. Along the way he discovers a whole new world of experiences, some welcome and others not. Will he find a way back to normal, or will he be trapped in a girl's body for the rest of his life?