To solve the country's low birthrate problem, the Japanese government set up Otona Kōkō (Adult High School). Adults over 30 with no sexual experience are forcibly enrolled into Otona Kōkō 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 Kōkō.
Episode 1
An elite banker named Eito is suddenly approached with an invitation to a school for virgin men and women over the age of thirty.
Episode 2
Despite several disadvantages, one of Eito's classmates manages to be the first to graduate. Consequently, Eito feels defeated and disillusioned.
Episode 3
Eito and Maki are stuck in the hell that is the Adult High School after the school staff sees through their deceitful plan to graduate.
Episode 4
False rumors about Eito crush the ray of hope that appeared after he swallowed his pride and told his childhood friend Haruka that he is a virgin.
Episode 5
The son of the Prime Minister responsible for establishing the Adult High School shows up as a new student and receives special treatment.
Episode 6
A picture of Eito and his 55-year-old boss wearing school uniforms leaks out via social media along with information regarding the Adult High School.
Episode 7
Eito confesses his feelings for Maki -- a first for him. But one thing after another prevents him from getting a response.
Episode 8
Eito and Maki begin to live together but they don't show any signs of 'going all the way.' Meanwhile, Sakura attempts to seduce Eito.
