Mr. Hiiragi's a popular teacher, favored by students for his enjoyable lessons. Chika, the class representative, looks up to him, and even has a crush on him that was supposed to stay secret... However, one fateful bag inspection day, their relationship takes a sudden turn. It should've ended without incident, but inside Chika's bag is something that wasn't there before! Mr. Hiiragi keeps her after school for a special lesson on how to use it... (Source: Renta!)

Otona no Omocha, Bosshuu sarechatta! Tsukaikata Oshieteyaru yo was published digitally in English as My Sex Toy Got Confiscated! I'll Show You How to Use It by Renta!, and as He Took My Adult Toy: "I'll Teach You How to Use It" by WWWave Corporation through Coolmic.