Uhura and Sulu have been best friends for years. They hang out all the time and have a grand time together. After years of friendship, Sulu realizes he's in love with Uhura. But he can't love her. She's dating Spock and would just put him in the friend zone. He keeps it to himself, telling no one. Not even his best friend, Chekov. It tore him up inside. Eventually, Uhura and Spock broke up and Spock left to help New Vulcan. Sulu was there to comfort Uhura and they grew even closer.