Baka de Yowakute Buzama demo Even If You're Stupid, Weak and Pathetic.

Synopsis

Kikumaru, a college student and part-time model, falls in love with a mysterious older man named Kuniyuki after falling for his seduction. However, after toying with Kikumaru, Kuniyuki suddenly cast him aside. Unable to let Kuniyuki go, Kikumaru follows him, leading him to one of Kuniyuki's host clubs... (Source: Shinshokan, translated)