Yukai (ユカイ, Yukai) is a young shinobi from Kumogakure and the leader of the Thundercloud Unit.

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.

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 team-mates 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.

Anime Debut: Naruto Shippuuden Episode #320

(Source: Narutopedia)