Rin, returning from club activities, falls asleep in the living room still in her uniform. Seeing her unguarded state and panty flash, her brother can't help but get aroused and starts masturbating while smelling her gym clothes. When she wakes up, she is disgusted. However, since she can't bring herself to hate her brother, she proposes to help with the masturbation to avoid things being awkward forever. But her brother still can't do it. Even when she agrees to his request to change into her gym uniform, he still can't do it. "Big brother, we're siblings so we can't insert, but just wearing this is fine. Go ahead and finish."
