Jiro Gomi, 29 years old, a virgin, and a socially awkward man. By day, he enjoys discussing otaku topics with like-minded colleagues at the job he's held for nine years. By night, he draws erotic doujin illustrations and pleasures himself. For Jiro, sex was something that only existed on a screen. However, his comfortable routine is shattered when a new employee arrives—Kuroko Yumesora, a black-haired, long-haired, glasses-wearing, voluptuous woman. Falling in love takes only a moment. So does stepping off the edge. A tale of sin and desire, told through the eyes of a weak man.