Three close adult friends—two men and Riho—take a graduation trip together. I plan to confess the feelings I have hidden for years, and my friend seems to support me. While I hesitate, however, sweet moans and pounding sounds come from the next room. Riho has given in to his late-night advance and even lets him creampie her. As regret and anger consume me, they keep passionately fucking. She meets my eyes, pretends nothing is happening, and continues moaning through rough sex with him, making me realize that loving her was a mistake.