Motoi

is a Kumogakure shinobi who is stationed on the Island Turtle.

Background
When Motoi was five-years-old, he and Killer B were good friends. After Motoi's father was killed during an attempt to subdue the Eight-Tails that had broken free from its previous jinchūriki, Motoi came to hate the Eight-Tails. B was soon chosen to be the beast's next jinchūriki and Motoi, just as many other Kumo villagers did, focused his anger towards B because he was to be the vessel of the beast. He once tried to assassinate B to avenge his father, but was disarmed by B easily. Despite having his face covered, Motoi assumed that B knew it was him, as B ungrudgingly greeted him as they used to with a fist bump. After this, Motoi could never bring himself to face B, and hadn't spoken to him for thirty years, but in time he came to admire B as a village hero.

Appearance
Motoi greatly resembles his father with his dark-brown, spiky hair and dark eyes. His most prominent feature is the dark green mark that runs down the bridge of his nose. He wears the standard outfit of a Kumogakure ninja, complete with hand and shin-guards as well as flak jacket. He also wears a light grey scarf around his neck.

Abilities
Motoi apparently is an expert tracker-nin, claiming after Kisame Hoshigaki was discovered, that even with his skills it would be nearly impossible to find him once he had left the confines of the island.

Ninjutsu
In light of his duty as the supervisor of the Island Turtle, Motoi seemingly shares a link with the barrier that surrounds the entirety of the enormous creature and its immediate surroundings, allowing him to accurately locate the position and/or quantity of individuals either entering or departing through this structure, supposedly without the need to contact those who originally constructed it. However, this capability is restricted only to the moment of passage through the barrier, meaning he cannot sense a person's presence once they are within the interior nor can he detect them if they are able to circumnavigate the barrier entirely through certain methods.

Nature Transformation
In the anime, Motoi has shown proficiency in Lightning Release, using a technique that could strike the area surrounding the user, which was seemingly powerful enough to temporarily halt Fukai in Tailed Beast Mode.

Summoning Technique
Motoi's contract allows him to summon owls, which he often employs as means to facilitate long-range communication by utilising them as carrier birds.

Confining the Jinchūriki Arc
Motoi greets Naruto and his Konoha escorts when they are brought to the island and takes them to their lodgings. After arriving, Naruto tries to get B to train him in controlling his tailed beast. B refuses, so Naruto comes to Motoi for help with convincing B, claiming that he is too stubborn. Motoi grows angry with Naruto for insulting him and insists that B must have a good reason. He takes Naruto to the Falls of Truth and instructs him in how to use it, explaining that it will reveal why B has misgivings.

Naruto meets an evil version of himself that he cannot defeat. He requests Motoi to ask B how he defeated his inner demons, but Motoi says that he is in no position to ask anything of B, having once tried to kill him. He tells Naruto about B's past and Naruto leaves to think. Motoi is later attacked by the giant squid that lives near the island, but B saves him. He apologises for trying to kill B when they were kids, but B reveals that he holds no grudge and forgives him, lifting his fist. Motoi sheds a tear as he realises B is still his friend, and they bump fists. After Naruto beat his dark self, Motoi left the group to report back to Kumogakure.

Motoi later leads Might Guy and Aoba Yamashiro to the falls. As they arrive they find Kisame Hoshigaki fleeing the area. Motoi warns them to stop Kisame before he can leave the island, or else he will no longer be able to track Kisame. Guy succeeds in catching Kisame but he kills himself before they can ascertain what he knew. They try to check the intel he had with him, but it is booby-trapped and they are imprisoned while a shark swims away with the intel. When B cannot catch up to the shark, Motoi sends an update to the Shinobi Alliance with one of his owls.

Despite the security breach, Motoi assures the Konoha ninja that Akatsuki will not be able to find the island because it is constantly moving. When Akatsuki soon afterwards attacks the island and stops the island's movement, Motoi goes outside to see what is happening. They find Kabuto, who immediately goes after Yamato. Kabuto escapes with Yamato and Motoi informs the Third Tsuchikage of what happened.

Trivia

 * Motoi is a Japanese word for "base".