The guardian that has the power of the moon and the last judge of the Clow Master/Mistress. He was created by Clow Reed, his former master before he had sealed him into the Clow Book before he died. He is a really serious person and all he cares about is himself and his master. He usually just stands around doing nothing.

Like Ruby Moon, he also has an unknown gender. Even in his temporary form, Yukito also has an unknown gender but dresses himself as a guy.