Rio went to Okinawa for a school event and stayed over at her relatives' house on her way back. When she meets her uncle and cousin for the first time in a while, they are captivated by her fully grown body, especially her breasts. The tan lines from her school swimsuit are clearly visible, making her look even more erotic. What's more, she is flustered when he rubs his breasts against her defenselessly. She has sex in the bath with her cousin! She even has a night-time threesome with her uncle and brother!