Mesu Kyoushi 4: Kegasareta Kyoudan 4

Yuuri's nephew, Kazuya, licks and rubs Yuuri's innocent body. He rapes her and takes her virginity. She has an intense climax and urinates on her "older sister's" desk. She complies with these and more indecent orders that she is given. She is forced to give one of her students a handjob during class and to perform fellatio while naked in the audiovisual room. Yuuri is humiliated in nearly every way imaginable, and Kazuya points out her penchant for exhibitionism. "C-Cut it out! I only feel shame from doing this!" Yuuri vehemently denies it, but as Kazuya forces her to sexually service him on camera, despite Yuuri's continued denial, a smile of pure ecstasy floats to the surface.