When her college-aged younger brother moved to Tokyo and needed a place to stay before finding his own apartment, he ended up living with his older sister. While sharing a home felt natural at first, the age difference became more apparent, and the situation left him slightly uneasy. However, his sexual desires proved uncontrollable. One day, he found himself in the bathroom with her—an act that had been normal during childhood, but now felt inappropriate. Her slender body and modest yet defined breasts ignited his lust beyond restraint. She quietly moaned, her soft cries echoing through the silence. Though he knew their intimacy was incest, he could no longer hold back.