C

is a jōnin-level shinobi from Kumogakure.

Personality
In contrast to his easy-going partner, C is portrayed as a very serious individual normally seen with a look of self-assured confidence on his face. He often puts duty above all else as shown when he told Darui there was no time for rest upon their return from the Kage Summit as they had to begin planning immediately. He also seems to have a slight dislike for Konoha ninja, calling Naruto's group "Konoha dogs".

Appearance
C is a young man with short blond hair and dark eyes. He wears a sleeveless black shirt with a one-strap-over-one-shoulder white flak jacket, forehead protector, black elbow-length arm guards, and the red and white Kumogakure shin-guards.

Abilities
C is a sensor type shinobi, allowing him to sense the chakra of others even from extended distances. Additionally he is a medical-nin which allows him to play an even greater support role on the battlefield. He also appears to be very knowledgeable on foreign shinobi techniques, as he is shown recognising Sasuke's Mangekyō Sharingan along with Amaterasu. C was able to deduce how Sasuke's Blaze Release worked after only seeing it once. C is a skilled genjutsu user, as he was shown using Lightning Illusion Flash of Lightning Pillar, followed by a second genjutsu within the first.

All of these abilities also imply a mastery of multiple skills requiring very fine chakra control.

Also of note is when he went to defend the Raikage from the bodyguards of the other Kage he took a defensive, taijutsu stance, implying he is competent in close combat as well.

Five Kage Summit Arc
C and Darui were chosen to escort the Fourth Raikage to the Kage Summit in the Land of Iron. During a brief rendezvous with Team Samui while en route, C sensed that they have been followed by Naruto Uzumaki, Kakashi Hatake, and Yamato and after the Raikage spoke with the Konoha-nin, they continued on their way. Once they arrived and the meeting began, C and Darui came to the Raikage's defence following his outburst, blocking the attacks of the other Kage's bodyguards. After being told to stand down, they returned to their posts after things settled down, only to again come to the Raikage's side when White Zetsu appeared. White Zetsu revealed that Sasuke Uchiha, Killer B's captor, was nearby, so C and Darui accompanied the Raikage in tracking Sasuke down.

C located Sasuke and his team and reported a number of samurai casualties as they got nearer. When they arrived, C launched an attack with his Lightning Illusion Flash of Lightning Pillar technique to blind Sasuke and his team, creating an opening for the Raikage and Darui to attack. The Raikage then instructed C to find and eliminate Sasuke's sensor. C was not able to defend himself properly during his search, and despite Darui's attempts to keep him safe, he is struck by one of Sasuke's genjutsu and passed out. Darui later revived him and helped him get on his feet, and together they observed the Raikage's fight with Sasuke. The Raikage was eventually struck by Sasuke's Amaterasu and was forced to cut off his arm. When the fight was interrupted by the Sand Siblings, C used medical ninjutsu and stopped the bleeding and silently worried about how far the Raikage was willing to go.

While the Raikage was being healed, Sasuke escaped. They followed him to the Summit hall, where Tobi explained his Eye of the Moon Plan to them. As part of his explanation he revealed that B only pretended to be captured; C sighs at this most recent example of B trying to get some vacation-time, which did not surprise Darui. After the formation of the Allied Shinobi Forces, C joined the Raikage in searching for B. Before they leave, C told the samurai that two members of Sasuke's team were still in the area.

From several miles away, C was able to detect B's chakra contained within a large sphere of water. When they arrived there, they found B fighting Kisame Hoshigaki. C thanked Kisame for producing the water dome and thus, inadvertently helping them find B. After Kisame was "eliminated" they all returned to Kumogakure. C later attended a war council meeting where he advised the Raikage on how to form a reconnaissance team to find the Akatsuki base.

Shinobi World War Arc
When the war began, C was placed in the Sensor Division. C was a bit unsettled since it is the first war he would ever fight in. However, Ao told him that if they did their jobs well, they could have a huge impact on the outcome of the war and not to slack off.

Video Games
In Naruto Shippūden: Ultimate Ninja Storm Generations, C is a support-only character.

Trivia

 * Shī is the Japanese pronunciation of the letter "C". This parallels J's name, which is the pronunciation of the letter "J", and Killer B's name, as "bī", the Japanese pronunciation of "bee", is also the Japanese pronunciation of the letter "B". The same applies to the Fourth Raikage's name, A.
 * In Naruto: Shippūden episode 261, when deploying with the Senor Unit, C is not present like he was in the manga. He is instead replaced with someone else.