Wakarete Yaranai!

Watase Akira, a high school student, notices that his classmate Watari Fumiya, who sits behind him, is extremely popular with the girls. Out of curiosity, or perhaps even as a joke, Akira decides to try and date Fumiya, thinking it might serve as good camouflage for Fumiya, but turns out...!? (Source: Ichijinsha, translated)