ORECS-648 Two pairs of siblings—an older sister and a younger brother—try to act like, “I-I’m not getting excited by seeing my family naked,” but immediately take it back and end up feeling strongly drawn to each other, crossing a line they should never cross at rocket speed. Sister: Yura (27) / Brother: Takeshi (23); Sister: Mami (26) / Brother: Shota (22)

[Group 1] Older sister: Yura (27), department store employee / Younger brother: Takeshi (23), cram school instructor [Group 2] A close sister and brother take on a strip rock-paper-scissors challenge! I’d never get excited over my sister’s body. The younger brother, who is inexperienced, is trying to act tough. Thinking that his sister is quite attractive and well-endowed, the game begins. As the two keep removing more and more clothing, the earlier remark becomes embarrassing. Before long, things turn into a secret, forbidden first-time encounter that must never be found out by their parents.