Risa runs away from her home, and her uncle's house is the only place she can go to. The uncle has been lonely for a long time, and can't help but notice how much his niece has developed...

Konna Mune demo Aisaretai!! (These Breasts Want to be Loved, Too!) High school student Ookoshi discovers the secret of his well-endowed classmate, Takita—it turns out that Takita does not have the breasts that everyone around her believes her to have. Fearing that Ookoshi may expose her secret, Takita "gives" him something irresistible as an incentive. Souda Imouto to Renshuu shiyou. (That's Right! I'll Practice with my Sister!) After arranging a meetup with a girl online and thinking that it may escalate into something lustful, Ami's older brother decides to practice having sex with Ami. Of course, she is not willing to let her brother have his way with her, unless he completes a certain "challenge."

Kon Katakura rarely attends classes, but when she does, her behavior is poor and her performance is mediocre. When the new homeroom teacher Kurosawa arrives, the two soon end up in a relationship quite unlike other students'. Through ups and downs, the couple struggles to define their feelings for each other. The only way they are able to manifest their affection is through passionate sexual intercourse, in which they indulge day and night. Kon moves to her new boyfriend's apartment, shunning her family and classmates, in an attempt to find meaning in their half-hearted and cursory relationship