腰痛の虫
こしいたのむし

Translation: lower back pain worm
Habitat: the kidneys

Appearance: Koshiita no mushi are infectious yōkai worms with black heads, white bodies, and long, pointed beaks like birds.

Behavior: Koshiita no mushi live in the kidneys and affect the lower back.

Interactions: Koshiita no mushi use their beaks to peck at their host’s muscles from inside the body, causing all sorts of pain throughout the lower back. The lower back begins to feel heavy and sore, and in severe cases movement becomes impossible.

Treatment is accomplished using the dried roots of the thistle mokkō (Saussurea costus).