

The story revolves around Nayu Hayama, who embarrasses herself on the first day of middle school by accidentally showing her adult panties. As two other students, Yako Jingūji and Haruka Shiraishi, hear rumors of her engaging in "enjo kōsai", or compensated dating (which often is viewed as being close to or the same as prostitution), they investigate. They soon learn that Nayu is an 'underwear monitor' who tests new underwear products, and has great insight on what underwear people should wear. Nayu hopes to help everyone get through the vital stage of their life by opening an underwear club.
Nayu Hayama

Haruka Shiraishi

Yako Jingūji

Keigo Hayama

Kiyono Amahara

Hiroki Komachi

Tamaki Mizuno

Tsukamoto-sensei

Yōko Sagisawa

Principal

Ōkuma-sensei

Kōta

Kaori Seto

Komachi's older brother

Tsuzuki

Chigusa

Tanihara-sensei

Suzuki
