From the manga habit:

Taira works part-time at a convenience store with his senior, Ebihara. Taira just can’t get along with Ebihara. He’s a blunt, yet good-looking guy who effortlessly attracts lots of attention from many different female customers. Taira is the serious kind of guy who stays loyal to a single girl, thus it’s impossible for him to relate to Ebihara. After scolding Ebihara’s ways one day, Taira inadvertently stirs those powerful pheromones…?