Yukai

is a young shinobi from Kumogakure and the leader of the Thundercloud Unit.

Background
Yukai was a young prodigy from Kumogakure, well versed in kenjutsu and assigned to be the Thundercloud Unit's leader in the Fourth Shinobi World War.

Personality
Despite his young age, Yukai showed great courage and leadership skills, managing to keep calm and focused while facing certain death when he and his unit were cornered by nearly two thousand White Zetsu clones. He also greatly respects Omoi, referring to the older shinobi as, an honorific for "elder brother".

Appearance
Yukai has dark red hair, with two bangs, and golden eyes. He wears a white Shinobi Alliance forehead protector and a green vest, with white cloth around the waist. Like the rest of his unit, he also carries a large scroll on his back attached to arm straps. Additionally, he wears a yellow armband with the Kumogakure insignia, which was given to him by Omoi.

Abilities
Yukai has been shown to be proficient in Lightning Release; being able to use a powerful combination technique, with the assistance of his unit and Omoi, which neutralised a large number of White Zetsu. As a member of the Thundercloud Unit, he is considered to be considerably skilled in kenjutsu, despite his young age.

Shinobi World War Arc
During the Fourth Shinobi World War, Yukai and the rest of the Thundercloud Unit, was sent to the Seventh Front in order to back up the Amphibious Search and Destroy Unit, who had been overrun by two thousand White Zetsu clones. Sometime during this, they became trapped within a large statue on the battlefield after the White Zetsu used the surrounding, poisonous red soil to create a vast smokescreen of poisonous gas. After speaking with his teammates within the statue, Yukai and the others emerge to fight the Zetsu and face their fate. In the ensuing fight, Yukai is injured, however, Omoi appears and fights alongside them. At this point, using the Lightning Release Co-Operation: Thunder Bomb technique, the group is able to neutralize and finish off the remaining White Zetsu.

Trivia

 * Yukai bears a very strong resemblance to Karui, another shinobi from Kumogakure.
 * When written as 愉快, "yukai" means "pleasant, happy".