She knows how good the feeling is with her ears, and she knows how many men are there with her eyes...Momono-chan, Momo-no-Yu's poster girl, is a shy virgin. On the other hand, Satojiri-kun, a part-time worker, wants to have sex with his female friend every day at the Momo-no-yu where he works part-time. One day, high school students Katsu-chan and Momono-chan witness Satoshiri-kun and his female friend's ``scene''. Moreover, Momono-chan ends up promising to have sex with Katsu-chan, a cute high school student. Her chance to lose her virginity has finally arrived, but Momono's serious personality gets the better of her, and something terrible happens. What will be the fate of her Momono-chan and how...! ? In the bonus 4-panel at the end of the book, Bubu-chan, who played an active role in the main story, appears as a cute mermaid!