Oki the migrating ninja was a ninja that masqueraded as Mōsō in the Land of Birds. In disguise, he served as Chief Advisor to the daimyo, Owashi. He leads The Wandering Ninja. Despite being its leader, Oki's skills do not seem on par with those of his group. When Mōsō was chief adviser, he secretly poisoned Owashi resulting in his death. Sagi (who was really Toki) took on the guise of Noroimusha in hopes of avenging her father. When this threat occurred, Mōsō sent Chishima to the Konoha for help and Tsunade dispatches Naruto Uzumaki and Team Guy (minus Rock Lee) to the Land of Birds. When Chishima overheard Mōsō's true plot, he got away and barely escaped Nagare, Hokushin, and the other Wandering Ninja whom Mōsō dispatched.
When it came to the final conflict, Mōsō trapped her in a imitation jutsu (and discovering Toki's duo identity at the time) as Naruto, Neji Hyuga, Tenten, and Kakashi Hatake arrive. Mōsō eventually makes off with Toki and he leaves the Leaf Ninja problem to Hokushin and the other Wandering Ninjas. Despite this, Naruto tricked him into revealing his true self when he used water clones to disguise his position. During the attack, Chishima was wounded by Oki. Naruto defeated him with Naruto Uzumaki Barrage. Oki was handed over to Toki, and Naruto requested that he be forced to repent for what he had done.