Wataru Won't Sleep with the Same Girl Twice

from Renta!:

What does it mean when someone loves you, but doesn't want to take it to the next level? Ayaka works at a college as an administrative assistant, and one day, Wataru, the hottest guy on campus, tells her he likes her. Having seen him a few times, Ayaka thinks he's nice enough, but there are rumors he's with a new girl every day! One such girl even tells Ayaka that Wataru's awful, though Ayaka isn't really sure why... When Ayaka asks Wataru himself, he says it's because he has one condition for anyone who dates him... In the middle of a packed train, where anyone could catch them in the act, Ayaka pretends to be a meek secretary... who gets felt up by Wataru! This is all down to his "condition"...!