The first year of the Kyoho era. The land is ruled by the eighth shogun Yoshimune Tokugawa. 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 “black Threads” before every catastrophe, which causes the panicked villagers to drive her away into the snowy mountains. One day, a young man going by the name of Oniwaban appears before her. This is a story in which a girl encounters “non-humans,” and learns about love.