CMC-106 - Black-haired sisters Yasha, butt competition, full-hole assault and molester Ichika Aimi, Risa Sakamoto

Natsuko, a good-looking elite office lady, and her younger sister Risa, who love the same man. The older sister goes crazy with jealousy and asks a certain man to discipline and train her younger sister, but the extreme harshness eventually reaches Natsuko as well, and the sisters train together at the same time, exposing each other's lewdness...