Slave-Colored Woman Teacher 4 Asami Ogawa (2010)

Mizuki Sakaguchi is a dedicated English teacher at Kusunoki Girls' High School, engaged to her boyfriend Naoya. However, her life takes a dark turn when she's coerced into a slave-like situation. She's forced into oral sex and other degrading acts, highlighting the theme of a gangbang and abuse of power. The central kink revolves around her enslavement, humiliation, and exploitation, showcasing a disturbing scenario of non-consensual acts.