Sensei Otona No Etchi O Oshietekudasai Koshigaukuhodotsukarete Dakareru Sefurekeiyaku

He doesn't make it a habit of screwing his former students... but if she's this insistent... Mitsuki was devastated when her high school teacher and crush Mr. Kamiya told her he was only into mature women. One day, after years of improving herself, she comes home to find her boyfriend cheating on her and decides to drown her sorrows at a bar. It turns out the man drinking next to her... is Mr. Kamiya himself! They haven't seen each other in seven years, and he intends to explore every inch of her beautiful body, whether she wants him to stop midway through or not... Mitsuki can't believe the waves of pleasure lapping over her body...! She doesn't want it to be a one-time only experience, though. Willing to do whatever he wants, the two enter into a limited-time-only friends-with-benefits partnership!