Ippei is a burdened part-time worker who always makes mistakes and causes trouble for those around him. Yumi, a senior who works at the same store, volunteers to give Ippei intensive training after closing time to help him become a full-fledged employee. "Don't worry, Ippei, I know you can do it! Have confidence!" Ippei is smitten by Yumi's encouragement and kind smile. Then, an incident occurs and the two suddenly become close! Without either of them taking the initiative, their lips end up touching, and they have a lewd encounter in the store after closing time...