A Karakuridoji representing ultimate good created by Dr. Dunstan. His masters are two reincarnations of Yamato Agari, in the Edo period and in the modern day.
Ultimo first met his master Yamato in the Edo Period (12th century), when Yamato was an infamous bandit who tries to rob Dr. Dunstan., not knowing that Ultimo and Vice were inside the cases. After seeing him for the first time, Yamato believes that he and Vice are human boys and is appalled by the thought of Dunstan locking children in boxes. Vice then awakens beside Ultimo, upset from the racket made while he was asleep, and begins to kill Yamato's comrades (vaguely resembling Yamato's friends and others from the 21st century) one by one, until Yamato steps up along with the remaining comrades to defeat him. Ultimo steps in, and defeats Vice for the time being (his whereabouts afterwords are unknown). Ultimo then becomes Yamato's page, and travels along with him and the bandits for an unknown amount of time.
In present day (21st century) Farmless City, Tokyo, Ultimo was found in the mountains by an antique shop owner and (after the man believes he is a doll) is put in the antique store to be sold. He reunites with Yamato once again when Yamato visits the shop, along with his best friend Koidara Rune, in order to find a gift for Sayama Makoto. Ultimo awakens and jumps from his glass case to hug Yamato, only for the latter to be overly-shocked because not only does he not remember Ultimo, he was stabbed with the broken glass on impact. After Yamato and a confused Rune leave in a hurry, Vice appears and proceeds to attempt to slice the bus Yamato is on in half only to miss the mark due to Ultimo's appearance. After Ultimo realizes that his opponent has already found a new master, Vice claws to his spirit sphere, the only thing one needs to destroy to kill a Karakuridouji. In a desparate attempt to save Sayama (although she was never in danger at all), Yamato jumps out of the bus (still being held in the air by a hurt Ultimo) and tries to hit Vice with his schoolbag, only to be stopped half way by Ultimo. He was touched that Yamato is the same as his past self and destroys Vice, cutting him in half, leaving him to be retrieved by K.