Brother and sister take a bath together after 10 years. The younger brother, a virgin unable to suppress his erections, and his older sister make love every day. (Yui Mahiro START-371)

SODSTAR x Momoiro Family Collaboration Project. A college student's older sister secretly harbors feelings for her younger brother. Mahiro, determined, enters him naked while he's showering. Ten years later, they bathe together again. The startled brother's penis gradually grows larger, crossing the line. From then on, they repeatedly desire each other's bodies, beginning forbidden intercourse without condoms…