Oddities have existed throughout history, with some tales of them dating back to 600 years ago. Stories about vampires, a monkey's paw, shikigami, wanderers in the mountain mist, murderous felines, mermaids, wolves, golems, and, most terrifying of all, humans, have been collected by so-called "oddity specialists." The purpose of these specialists is to combat, regulate, and, most importantly, solve the many mysteries behind the circumstances these oddities create.

Monogatari Series: Off Season follows eight protagonists—some specialists, some oddities themselves—as they interact with the world of aberrations, often landing themselves in dangerous situations due to their own mischievous doings.