The Dissolute Gal and the Virgin's Lust

A virgin otaku male student begs large-breasted classmate Natsuki for sex just once; she agrees to service him until graduation. They have oral sex and intercourse with creampie in the school bathroom. He later peeks on Natsuki having sex with teacher Kimono in an empty classroom. The next day she confronts him about peeping, takes him home for a second round of intense sex with creampies, breast milk, and marriage pressure. The following day the teacher has Natsuki explain male-female intercourse to the class, and she demonstrates by having sex with the otaku student in front of everyone until class becomes only sexual acts.