The young heir to a powerful Merchant, the Ayamaro, in the city where Kirara begins her search. His shielded lifestyle leaves him with a somewhat self-centered yet playful attitude on life, really a cover for a rather calculating, manipulative and cruel character. He falls in lust with Kirara upon first sight and seeks to add her to his harem. When Ayamaro is summoned to the capital, he becomes the new minister of the city of Kogakyo. However, Ukyo himself is soon summoned to the capital, where he is revealed to be a replicant of the current emperor, Amanushi, who sent Ukyo out to be raised by peasants and taught by merchants in the hope of creating a successor worthy to be emperor. After surviving a 3-day ordeal, Ukyo is proclaimed heir to the throne. He then murders the emperor to succeed him and launches a plan to pit the villagers, ronin and nobuseri bandits against one another to consolidate his control.

Ukyo has an extreme dislike for mechanical samurai, especially the Nobuseri and Kikuchiyo, because they remind him of his days as a peasant when he himself was terrorized by bandits.