From Yaoi Desire Revolution:
Nao, the introverted prodigy of the department, trembled upon hearing the handsome Kouji, who has an inseparable relationship with him, discussing his problems. The thing is Kouji is an ass “hunter” who can’t stop feeling sexual arouse when seeing beautiful ass? After devouring almost all of the girls in university, he began hitting on Nao, who has a beautiful round ass despite being a man!
This book includes the following stories:
1) The Cafe Called Love
2) Suki Dakara Itte Hoshikunai
3) Urge to Molest
4) Spring Comes to the Cafe