Akubi no mushi
欠伸の虫

Translation: yawning worm

Akubi no mushi is a red worm with a snake-like belly and fine hairs sprouting from its back. It lives in your heart.

When an akubi no mushi infects a person’s heart, that person begins to yawn uncontrollably. Not only that, this worm disrupts the blood flow to the heart, causing intense fatigue and drowsiness.

The cure for akubi no mushi is to drink a boiled concoction made from the galls of Japanese sumac (Toxicodendron vernicifluum).

I would say that I often feel like there’s a bug inside of me making me sleepy, although I usually try to cure that by drinking tea, not tree galls.