Satsuki Shinohara, a timid high school student, nearly faces a disastrous start due to a train pervert until Yamaguchi, the class 'delinquent', comes to her rescue. Despite Satsuki's efforts to befriend him, Yamaguchi eludes her, surrounded by a cloud of notoriety. Undeterred by the challenge, Satsuki is determined to unveil the true depths of Yamaguchi's character.