Kaichou-sama no Oose no Mama ni

Ichika Okuzaki joins the student council to get closer to the flawless and pretty president Mahiro Sasamori. Except, the student council president is actually a hardcore masochistic pervert!! One day, Ichika finds Mahiro tying himself up and masturbating, but for some reason, Ichika gets threatened and forced to help with the bondage...! Ichika gets sick of Mahiro ignoring his feelings and only wanting Ichika to tie him up, so he decides to act for himself...

(Source: Renta!)