Kokuyō

was a fabrication, that was created to serve Kū and to lead the Akuta in order fulfil Ōnoki's desire to protect peace within Iwagakure and the shinobi world.

Personality
Kokuyō was a very serious and straightforward individual, viewing emotions and companionship as irrelevant and only things that will interfere with efficiency. He showed little trust in others and focused solely on his mission. He was shown to be very merciless, willing to kill allies to insure no loose ends should they fall behind. At the same time, he viewed it as mercy killing, letting them die with dignity. Getting stronger was his reason for living. He was very combat driven and perceptive individual, able to quickly see through his opponent's attack strategies. He has tremendous strength of will, able to quickly break free from a mind-controlling technique. He also talked in an old-fashion manner. Compared to his fellow artificial humans, he had no interest in emulating human nature, but rather viewed himself as a superior species.

Appearance
Kokuyō was a young man with long, wavy black hair and pale skin. He had angular, pupilless blue eyes and a prominent nose. He wore a purple tunic over a black body suit, his hands and lower face covered by bandages.

Abilities
Kokuyō noted that while he was unable to use jutsu, he had superhuman capabilities, being able to defeat several Konohagakure jōnin alongside an Akuta with ease.

Physical Prowess
In battle, he displayed blazing speed, easily to able catch Sarada Uchiha off-guard even with her Sharingan and likewise had considerable raw strength in his strikes. He showed remarkable prowess with his pair of tonfa, using them akin to a boomerang, launching them at a target while ricocheting them back to his hand with ease.

Mitsuki's Disappearance Arc
The day after a Five Kage Summit was held in Konohagakure, Kokuyō and Sekiei attacked Saō and Uō at the village's entrance, leaving both men in comas, before leaving with Mitsuki. On their way back to the Land of Earth, Sekiei took an open liking towards Mitsuki as an artificial human. He began talking about how Mitsuki's being would help in advancing their goal, only to be interrupted by Kokuyō, who didn't trust Mitsuki with such information. As they approached the Land of Earth's boarder, Kokuyō noticed that they were being pursued by Konoha-nin. Sekiei was sent ahead with Mitsuki while Kokuyō engaged the pursuers. He quickly dispatched the chūnin, and then met a group of Konoha genin who were unofficially pursuing Mitsuki.

He made his views and goals clear as he began berating the children. Showing value in his self-worth, the artificial human quickly pressured the genin with his inhuman raw might. After being impressed by their team-work of Boruto Uzumaki, Shikadai Nara, and Sarada Uchiha to take out an Akuta, he decided to start fighting seriously. The genin were saved by the timely arrival of Chōchō Akimichi and Inojin Yamanaka. With the team together, the Ino-Shika-Chō decided to hold off Kokuyō while Sarada and Boruto went on to find Mitsuki. Despite the team's perfect formations, Kokuyō easily repelled them all, forcing them to retreat. Kokuyō then rushed to catch up with other Konoha-nin. He arrived in time to see Sekiei struggling against Boruto's snake summon Garaga. Rather than help, he decided to see how things would play out first. He watched as Mitsuki came to the weakening Sekiei's aid and made his intention of joining the artificial humans clear as he struck Boruto hard with a Lightning Release. In watching the unhesitating action of Mitsuki against his former team-mate, Kokuyō came to trust Mitsuki as the group left the Konoha-nin, finding them too pitiful to bother killing.

Later, still having some concerns about Mitsuki, those thoughts were forgotten as Sekiei's body began breaking down. Taking a chance, he left Mitsuki with his weakened ally and returned to base for help. After getting help from Kirara and Kakō, they returned midway to find Mitsuki carrying Sekiei. As Kokuyō the others continued to grow suspicious of Mitsuki, the partially treated Sekiei vouched for Mitsuki, insisting that the boy truly came of his own free will on the goal of learning who he truly is.

Once arriving at their headquarter, he discussed with Kakō how best to deal with Mitsuki, as the plan ultimately was to dissect him. Kokuyō however calmly said they would wait for orders. After Ōnoki went missing, Kū had Kakō and Kokuyō use more Akuta to search for him. When Kirara's body began weakening, it caused her genjutsu on the village officials to end. Realising that they had to take drastic measure to keep their work secret from the outside world, Kū launched a hostile takeover. Once succeeding, the artificial humans began growing irritable at Kū's refusal to try a human heart transplant on them, which could likely save their lives, on the grounds that they did not yet have Ōnoki's permission.

When Ōnoki was returned however with the Konoha-nin, he firmly refused to sacrifice any lives to further his goals. Seeing the elder as too softhearted to do what was necessary, Kū incapacitated him and decided to move forward with his plans. Before they could, Shikadai intervened, using a diversion to help his fellow genin escape. They were soon intercepted however by Kokuyō. Shikadai and his team-mates decided to face the foe while Boruto and Sarada moved on. Kokuyō's advanced physical prowess quickly adapted to the Ino-Shika-Chō's previously shown attack patterns and forced them back. Using a plan of Shikadai, they were able to lead Kokuyō into a trap. While nearly working, the foe proved to strong and moved in to finish Inojin. Instead, Inojin was saved by the efforts of the tiny Akuta Inojin befriended and named Akkun. The creature's efforts let Chōchō land the final blow to finish the foe, leaving Kokuyō astonished that such "weak" foes could defeat him. Shikadai explained firmly that it was because they have compassion and trust in others that they learn to compensate for the shortcomings and rise above them. As the genin explained the true value of one's heart, Kokuyō scoffed at it on the grounds that he had no actual heart. Shikadai however corrected him by noting it was only because he had a heart they could defeat him. Kokuyō pondered on Shikadai's views before finally dying.