Classmate no Moto Idol ga, Tonikaku Kyodou Fushin nan desu.

Saegusa is a high school student who was once an idol but has since retired. She is attractive, smart, and well-liked for her cheerful and friendly nature. Takuya, who works part-time at a convenience store, is aware of a hidden aspect of Saegusa's personality that others are not. On a regular day, a woman with an unusual disguise appears at the store. Her presence raises suspicion, and it is likely that she is Saegusa.