Chou! Monzetsu Curriculum

The Monzetsu series features girls with bulging stomachs and throats filled with cocks and cum, and x-ray shots of the action happening inside their bodies!

In this volume a two boys challenge the girl dating both of them, a girl and her boyfriend awaken her elder sister's sexuality, a sister and brother get close in the bathroom, a teacher finds out a students secret during a makeup test, the head of the boys fencing club gets his revenge after a contest with the girls gives them command of the training dojo, a chanbara team get drunk before a tournament, a doctor's son is left in charge of a clinic, a tutor rewards her student for passing his exams, and a male student blackmails a classmate with evidence of shoplifting.

(First paragraph: Manga-Updates. Second Paragraph: MAL)