Ane Kyoushi ~Kairaku ni Yureru Soukoku no Omoi~

Shuichi was sexually abused by his older sister, Ayaka, when he was a kid.... That bitter experience made him crooked.... One day, Ayaka starts working at his school. Since she is such a beautiful woman, she soon gets popular among the students and teachers. Shuichi thinks, "You ruined my life, but you are now acting as if you did nothing bad to me...." He finally decides to make her his sex slave.... At first, he wears a mask and forcibly has sex with her. And then, he gives her various orders.... Like this, she gradually gets addicted to her indecent life....