Kyoushitsu no Yugami
Abusive relationship between an older male teacher and an underaged male high school student incorporating dubcon, exhibitionism/public sex, secret vibrators, sounding, blackmail and humiliation.
Otoshimono
A street-curb pick up leads to a drinking session and gay sex for a young man who is concerned about keeping his guest safe from physical abuse.
Sono Yubi De Hagashite
A teacher is drawn to a quiet, over-dressed young man in his class who seems to be enduring abuse by fellow classmates. The reality is much, much worse. In fact, it's so bad, pity overwhelms any other feelings at this stage and the cross-dressing aspect feels wrong for all the wrong reasons.
Hanamachi Monogatari - Hatsuzakura Mau, Yoru No Shitone