Gochisousama ga Kikoenai!

Gochisousama ga Kikoenai! summary:

"You might end up having your appetite satisfied instead." The boss that he admires so much has been possessed by an incubus?!
Super-duper earnest salesman Utsuse has been striving each day to be like his serious, straight-laced boss, Togawa, who also happens to be the top performer in the sales department. Then one day, an incubus possesses Togawa and transforms him into an arrogant sadist. "Let me fuck you if you want to save your boss." Pressed by the incubus (who’s using Togawa’s body), Utsuse ends up being pounded to save his boss's life?! Yet even during sex, Utsuse's gentle boss and the arrogant incubus take turns toying with him...?!
A frustrating, obsessive love between a serious man possessed by an incubus and his extremely earnest, and courageous subordinate.