Transported to another world where women have few options, Haru is working at the Blue Cat Nocturne brothel while her otaku classmate gets to be an adventurer. The customers often insult and abuse her, but she works hard, keeps her spirits up, and even gets a raise. Sometimes her work is even rewarding, as when naive Sumo loses his virginity to her. But men are just her job—till a mysterious customer who only comes to drink catches her attention.