The zashiki-warashi have been seen many times in the anime.
In the fifth anime, there are two zashiki-warashi that are the 12th of the chosen 47 Yōkai Warriors and the representatives of Iwate. Their marks are located on the left (male, green) and right (female, orange) arm when they're knotting their arms.
Powers and Abilities
Fortune Manipulation: He is able to bring good luck to the people of the home he inhabits, his presence alone already starts this. He can also do so by raising his arms and exerting power, creating a yellow aura around him in the process. However, the more power he exerts, the more weakened he becomes. He is also able to manipulate the fortune that the family has gained, when doing so a red aura surrounds him and the fortune as they are lifted from the ground. Selective Invisibility: Zashiki-Warashi is able to make him invisible to those he chooses. With enough focus, those who could not see him will be able to afterward.
Teleportation: Similar to other Yōkai, he is able to disappear from sight, fading slowly while doing so.
Zashiki-Warashi (座敷童/座敷童子, Tatami Room Child), sometimes also called Zashiki-Bokko (座敷ぼっこ, Zashiki-Bokko), is a Japanese yōkai, stemming from Iwate Prefecture. The legend of the Zashiki-Warashi is similar to the legend of the Russian domovoi.
The name breaks down to zashiki, a tatami floored room, and warashi, an archaic regional term for a child. The appearance of this spirit is that of a five or six year child with bobbed hair and a red face. Zashiki-Warashi can be found in well-maintained and preferably large old houses. It is said that once a Zashiki-Warashi inhabits a house, it brings the residence great fortune; on the other hand, should a Zashiki-Warashi depart, the domain soon falls into a steep decline.
To attract and maintain a Zashiki-Warashi in the home, it is said the spirit must be noticed, appreciated and cared for properly, much in the manner one would raise a child, though too much attention may drive it off. As the Zashiki-Warashi is child-like in nature, it is prone to playing harmless pranks and occasionally causing mischief. They might for instance sit on a guest's futon, turn people's pillows over or cause sounds similar to kagura music to be heard from rooms no one uses. Sometimes they leave little footsteps in ashes. There are different variations as to who can see the Zashiki-Warashi; usually this is limited to inhabitants of the house, sometimes to children.
The Ryokufūsō in Kindaichi-Onsen, which burned down on October 4, 2009, was famed for its Zashiki-Warashi. Yōkai similar to Zashiki-Warashi in other parts of Japan include the Makura-Gaeshi in Ishikawa Prefecture, the Akashaguma or Kura-Bokko in Tokushima Prefecture and the Akashaguma living in the Kotohira Shrine.