The first year of the Kyoho era. The land is ruled by the eighth shogun Tokugawa Yoshimune. Repeated incidents caused by monsters in the town of Edo upset and frighten the people so the Tokugawa shogunate establishes the “Oniwaban” to maintain public order and secure the town. Seasons pass—to year 11 of the Kyoho era. A girl in a village far from Edo has the power to see a “black thread” before every catastrophe and the panicked villagers drove her away into the snowy mountains. One day, two young men from the Oniwaban appear before her. This is a story in which a girl encounters “non-humans,” and learns about love.