Motoi

guides Naruto Uzumaki and Yamato through the island, where Killer Bee trained to control the Eight-Tailed Giant Ox.

Background
It was revealed that Motoi and Killer Bee were good friends in childhood. Thirty years ago, however, the Eight-Tailed Giant Ox was a monstrously wild tailed beast, which despite having been sealed into various jinchuriki failed to contain it and use its power. It usually took drastic measures from Kumogakure's ninja led by the Third Raikage to calm down and re-seal the tailed beast into a sealing pot. This effort caused many lives lost including not only those of past jinchuriki and Kumogakure ninja but that of Motoi's father. When Bee was chosen as the new jinchuriki, the collective hatred of the community for the tailed beast affected Motoi's desire to avenge his father. This drove him to forego his friendship with Bee. Plotting to assassinate Bee, he ultimately failed but presumed Bee actually knew it was him who attempted the deed. Since then, he withdrew from Bee's presence

Fourth Shinobi World War arc
Motoi greeted Naruto, Killer Bee and the rest of the Kumo and Konoha-nin as they arrived on the island, and took them to their lodgings. After failing to get Bee to train him, Naruto asked Motoi how he could convince Bee to do so. Motoi reprimanded Naruto for speaking badly about Bee, and asked him if Bee greeted him. After Naruto said he bumped fists with him but accidentally made fun of rapping, he replied that Bee may have had his reasons for refusing to take Naruto under his tutelage, and then guided Naruto and Yamato to the "Falls of Truth," the place where Bee trained to control his tailed beast. He instructed Naruto to sit in a platform and close his eyes, which caused an evil version of Naruto to appear. After Naruto awakens, Motoi tells them that Bee was also hated by the villagers when he was younger. Naruto asks him to ask Bee how he controlled his Biju for him, but he refuses, saying that he tried to kill Bee once.

After telling Naruto of his unsavory relationship with Bee, he was once again attacked by the giant squid troubling the boats that arrived on the island. Though Naruto and Yamato attempted to rescue him with both their ninjutsu, Killer Bee was able to subdue the squid before them. Bee also revealed that he never held any grudge for Motoi when the latter asked for forgiveness.