START-371 Sibling bath after 10 years apart. The virgin younger brother, unable to control his arousal, and his older sister are having intimate relations every day. Mahiro Tadui

SODSTAR x Momoiro Kazoku collaboration project. A college-aged older sister had secretly been fond of her younger brother. Mahiro gathers her courage and enters the bath naked while her brother is bathing. It is the first time the two have bathed together in 10 years. Her brother is startled, but their feelings gradually grow stronger, and they cross a line. After that, the two repeatedly seek each other out and become involved in a forbidden relationship.