Onna Kyoushi Yumi no Houkago  

Hot for Teacher, Onna Kyoshi Yumi no Hokago, 여교사 유미의 방과후, 女教師・裕美の放課後

Yumi is a woman who has dark hair and an hourglass figure. She's skilled at satisfying the needs of her students. However, she struggles with getting what she wants herself. Recently, she experienced a break-up with her fiancé and was sexually harassed by the Vice-Principal. This led to an orgy where she was repeatedly ravaged by the VP and some horny students. They made her swear to become their secret sex slave. Yumi's only hope now is Katsutoshi, a reluctant ally, and his girlfriend Keiko. Despite this, it may be challenging for her to break free from her sexual servitude since everyone seems to have a desire for teachers.