James T. Kirk/Relationships/Friendships/Hikaru Sulu

Though Hikaru Sulu was briefly an Enterprise physicist, he was transferred to the command division under Kirk's command, where Sulu became the ship's senior helmsman throughout the historic five-year mission. () Kirk relied on Sulu as a capable officer he could trust with the Enterprise conn in battle situations () and on away missions as delicate as the timeline-risky visit to the US 498th Airbase Group in Omaha, Nebraska, on Earth in 1969. () 
Sulu risked his career for Kirk on two occasions. Conspiring with his friends, he assaulted a security guard to liberate Dr. McCoy, and piloted the stolen Enterprise out of Earth Spacedock to the Genesis planet in 2285. () As captain of the Excelsior in 2293, he penetrated the Azure Nebula in Klingon territory in an effort to rescue his former captain before he was forced to turn back, () and he later joined Kirk in halting the Khitomer conspiracy. ()
Outside of their careers, however, the friendship between Kirk and Sulu was not especially close. Kirk was surprised to discover Sulu had a daughter, Demora, on the maiden voyage of the Enterprise-B. Chekov had to remind him that he had actually met her before, twelve years prior. ()