Zainin Tenkousei

Akihito is a prisoner who was not taught common sense, was isolated for 10 years, committed mass murder, and was sentenced to 500 years in prison. A system called "sinner transfer students" is proposed to him, which allows him to transfer to a problematic high school and reduce his sentence by solving school troubles. He infiltrates a delinquent high school, and sometimes an all-girls high school, and solves problems with his natural cheerfulness and violence. Will Akihito ever be released and get a free life...?