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

クラスメイトの元アイドルが、とにかく挙動不審なんです。, My classmate Shion Saegusa was idol. but she is unsure of behavior in front of me.

Miss Saegusa, who was once an idol but stopped her career at high school, is described as attractive and intelligent. She consistently exhibits a joyful demeanor and enjoys widespread popularity among her peers. On the other hand, Takuya has observed a different facet of Miss Saegusa. Today, at his part-time job at a convenience store, he encounters a woman with questionable attire and behavior, whom he suspects may be Miss Saegusa in disguise.

Classmate no Moto Idol ga, Tonikaku Kyodou Fushin nan desu. began as a web novel on Shousetsuka ni Narou on September 3, 2020. Micro Magazine-sha has released a revised and illustrated version of the series since January 20, 2022 under its GCN Bunko label.