Mammal, Hominid

Eiji is a guy who loves animals so much he will spend his entire paycheck to celebrate their birthdays. Today, he is as broke as always! He is also constantly frustrated, muttering he wants to go at it too while watching two lions copulate. But then, he wakes up in bed with his straight-laced co-worker Mitsuru, doing it with another guy for the first time...!?