Zashiki-warashi.

Zashiki-warashi (座敷童子, ざしきわらし) is usually perceived as a childlike presence rather than a fully stable body. Witnesses describe small figures with red or flushed faces, bobbed hair, and old-fashioned children's clothing, but many encounters stop at footprints, laughter, or the sense that one extra child is in the room. The yōkai belongs to the inside of the house, where a clear sighting is less important than the signs it leaves behind.

Its child form is central to its meaning. Zashiki-warashi is not merely a haunting child. It is a domestic spirit whose youth marks freshness, luck, and nearness to powers older than the family itself. The house becomes prosperous not in spite of the child's presence, but because of it.

Zashiki-warashi play pranks. They leave small footprints in ash, turn pillows, make spinning or kagura-like sounds at night, and tease both guests and residents. Yet unlike many household yōkai, they are welcomed rather than expelled. A family believed to host one is considered fortunate, and some households leave out sweets or keep a room especially suitable for a child spirit in hopes it will remain.

The real fear lies in loss. If the zashiki-warashi leaves, the family is expected to decline in fortune, health, or standing. This gives the spirit a rare role in yōkai lore. It is mischievous but beneficent, troublesome in detail yet auspicious in the long arc of a house's life.