Egoism Heat

Shouma Ootsuki's an omega and an office worker of marrying age. He's set up in an arranged marriage with a skilled alpha female and just goes along with the flow in a relationship with her. However, Shouma can't bring himself to take the big step, and when he gets drunk one night, he bumps into a mysterious alpha male named Kanata Tachibana and asks him to pretend to be his lover so that he can call the arranged marriage off. But, when they unexpectedly fall for each other's scent, they sleep together and Shouma finds that his life is now tied to Kanata's. This surprising relationship between the two changes them in various ways...

(Source: Renta!)