A record of a simple big-breasted college girl’s “sex length” with her big-breasted sister with a sexual desire that surpasses her virgin boyfriend. Ai Hongo.

Yuta begins to date Yume, his first girlfriend ever. He is a virgin and she’s an extremely nerdy woman, so it’s only fitting. But the thing is that after having sex a few times she is becoming more sophisticated, and her sexual desire is growing fast. So much so that it begins to become a problem for him…