Gomi Jirou, a 29-year-old virgin, has spent the past 9 years nerding out with his work colleagues about anime during lunch and drawing erotic doujinshi at night so he can masturbate. However, one day, this comfort zone of his is thrown into disarray by the introduction of a new colleague, Yumezora Kuroko, a bespectacled beauty with long, dark hair and a massive chest. It only takes a moment to fall in love, just like how it takes a moment to lose your footing. This is the story of a weak man's sins and sexual fixations.