Wanyūdō is the first of Ai's three companions. He generally appears as an old man whose eyes remains shut, wearing a traditional yukata with a long-sleeved haori, and a red scarf around his neck. When needed by Ai, he takes the form of the black straw doll that Ai hands to her clients in the series. He also frequently takes the form of Ai's coach with burning wheels when she goes to the human world to claim a soul. The coach bears the same black flame-crest that appears on the chest of those people who contract with the Hell Girl. Despite appearing quite mild-mannered, frail and weak with age at most times, Wanyūdō possesses considerable skills in martial arts and is capable of hurling fireballs and performing feats of inhuman strength. Wanyūdō's name is derived from the yōkai of the same name and means "A wheel entering the road". In episode 12 of Futakomori, it is revealed that he was the driver of a princess' entourage carriage, which fell off a cliff. The coach caught fire and all aboard were killed. As a result, he became a yōkai terrorizing people in the form of a flaming wheel with his own enlarged, infuriated face as a hubcap, until he met Ai and she invited him to join her as her first companion. Wanyūdō revealed to Ai his ability to shapeshift. Wanyūdō lives out his life in peace as a human after Ai dies at the end of the second season, but is soon recruited by Kikuri to become Ai's assistant again. At the end of the third season he comes to the aid of the newest Hell Girl, Yuzuki, but returns as Ai's assistant after she becomes Hell Girl again.