Aitsu Boukun Sugi Tannin no Gikei kara Fushidara na Shirei

He became my step-brother when my mother remarried, and he's always been sadistically nasty to me. From the time we starting living together the teasing escalated, leading to a more perverted angle. Then one day he becomes my homeroom teacher! At home and at school, the orders come thick and fast... Why can't I stand up to him...!?