2017年、政府は深刻な少子化に歯止めをかけるため、性経験のない30歳以上の男女を公的教育機関「オトナ高校」に強制入学させる「第二義務教育法案」を打ち出した。政府から突然、オトナ高校への入学を義務付けられたトップバンク行員の荒川英人は戸惑いつつも入学。卒業条件である「童貞卒業」を目指して30代から50代まで様々な学友と悩みながら人として成長していく。
To solve the country's low birthrate problem, the Japanese government set up Otona Koukou (Adult High School). Adults over 30 and have no sexual experience are forcibly enrolled into Otona Koukou by the government.
Eito Arakawa is a 30-year-old single man. He graduated from a prestigious university and works at a bank. He has received recognition for his work there. He is also physically attractive, but he has never had sex.
One day, he receives an entrance guide to Otona Koukou.
