Adapted from the manga of the same name, it tells the story of a martial artist who has trouble with everything he does and lives in a run-down old apartment. He learns from TV that his ex-girlfriend from junior high school, Hinata, was killed in a gang fight. One day, he was waiting for a train on the platform and fell onto the tracks. Just when he thought he was dead, he came to his senses and found himself back in junior high school 12 years ago. Later, he met Hinata's younger brother, Naoto, who told him what happened 12 years later and asked him to protect his sister. After the two shook hands, he returned to the modern era again.