Based on a seinen manga by Nakata Yumi, serialised in Comic High. Hayama Nayu is a newly enrolled junior high school girl, who has a strong principle in the way of wearing underwear. She is able to see if women around her are wearing fitting underclothes and cannot help pointing out their mistakes. In order to educate the students about the proper knowledge of underwear, she decides to set up the "Underwear Club." Note: the first episode was initially aired as an online preview on Bandai Channel.