A Story About an Experiment to Find the Answer to the Question, What Happens if You Give a Girl an Erotic Hobby with the [Hobby Modification App]?

Keisuke Sato, a sophomore in high school, happens to get a mysterious smartphone app called [Hobby Modification App].

Sato uses this mysterious app on five beautiful girls as if it were a game to solve a puzzle, but it turns out that their hobbies have really changed…