Ullr serves as an assistant to Kikko Hoshino, possessing a Daruma-like appearance. He holds knowledge of Kikko's true nature as a demon originating from another dimension. Ullr states she was sent to the human world as a candidate to become queen of the demon realm, tasked with finding a husband. He later observes a significant change in her circumstances, noting her emotional entanglements and loss of demonic powers have stripped her of her candidacy for demon queen. Ullr's known interactions center on conveying information about Kikko's origins and her altered status within the demon world hierarchy.