From Exiled Rebels Scans:

Takase Ai is a horny, enthusiastic university student who looks aggressive but who is actually an idiot. Cute girls from university invite him to a goukon and he happily accepts thinking “Alright, time to get some chicks!” But oh no, the girls cancel at the last minute. The four jobless guys who met each other at the goukon end up drinking together. After Ai complains that he wants to go home, the others’ reply is “Then how about we do it together?” and suddenly an orgy party begins!?