Hentai tells the story of unhappy Tachibana Yui-chan, who is caught in the clutches of a lecherous teacher. It didn't look like anything was going to happen - the young student was having a great time with her boyfriend Kou-chan. She didn't notice how the slutty Sensei was already weaving his skillful net around her. Yui quickly succumbed to persuasion and blackmail and became the teacher's sex toy...