Are The Sexy Buttocks Not Good?

Are The Sexy Buttocks Not Good? summary:

Ainosuke Hizaki (20 years old) is addicted to an** masturbation, which he started out of curiosity. One day when looking at dating sites on the train to see if someone could make him have an an** org***, he gets molested. Seeing something is off, an older handsome man, Okumi, helps him out and let's Ainosuke know that he's good at making guys c** from behind. Though the two don't have "s**", he makes Ainosuke come in a meltingly tender way! Then, however, Ainosuke, slightly dissastified, loses contact with Okumi...?