J

was a shinobi of Kumogakure.

Personality
J seemed to be a very brave man, or at least very loyal, as seen when he willingly trailed Sasuke and his team by himself.

Appearance
J was a dark-skinned, bald man with a flak jacket with one strap over one shoulder, and a black shirt underneath. He also wore a pair of black sports sunglasses and a forehead protector with a white cloth.

Invasion of Pain Arc
J and his partner, K, discovered that Killer B was fighting members of Akatsuki while transformed into the Eight-Tails. He sent words of his discovery to the Fourth Raikage and then used his messenger lizard to follow Killer B's opponents. He was later discovered by Sasuke Uchiha and Jūgo before being captured. J was later found slumped against the wall of the hideout by other Kumogakure shinobi.

Trivia

 * As is the case with several Kumogakure ninja, "Jei" is the Japanese pronunciation of the letter "J".
 * In Naruto Shippūden: Ultimate Ninja Storm 3, J's character model is used as a background Kumo shinobi. J himself plays no role in the story however, his model is also used as a support character in one of the game's mob battles.