Star Trek's Mr. Sulu (George Takei) remains one of the franchise's most popular and enduring characters, with an extensive history explored over the years. First introduced in Star Trek: The Original Series, Sulu is mainly remembered as the helmsman of the USS Enterprise under the command of Captain James T. Kirk (William Shatner). Although he acted as a supporting character during TOS, Sulu was integral to the show's main cast, specifically because of his role as a bridge officer on the Enterprise which often put him in the thick of the action during an episode's main storyline.
As a Japanese-American character on television in the 1960s, Sulu was a big part of the vision of greater diversity that Star Trek creator Gene Roddenberry worked to incorporate into The Original Series. This combined with George Takei's excellent acting skills cemented Sulu's popularity throughout TOS and the six feature films that followed the show. It also ensured that Sulu would go on to appear in other projects as Star Trek continued to grow, with the franchise adding more and more to his legacy even in the modern era.
Mr. Sulu In Star Trek: The Original Series & Movies 
While not present in the Star Trek: The Original Series' unaired pilot "The Cage", Mr. Sulu did appear in the second pilot "Where No Man Has Gone Before", which ended up airing as the third episode in TOS's first season. "Where No Man Has Gone Before" depicted Sulu as part of the Enterprise's science division, but subsequent episodes changed his role to that of helmsman, also granting him the rank of Lieutenant. Although rarely given a starring role, Sulu often stole the show during dramatic moments, such as his famous sword-fighting scene in season 1, episode 4 "The Naked Time".
Sulu was present for all six of the movies featuring the cast of Star Trek: The Original Series, where he had some especially memorable moments during the crew's adventures. While still acting mostly as a supporting character, Sulu was integral to the plot arc depicted from Star Trek II: The Wrath of Khan through Star Trek IV: The Voyage Home. Sulu helped Kirk steal the Enterprise in Star Trek III: The Search for Spock and piloted the Klingon ship to the future in The Voyage Home. He also finally received a first name, Hikaru, on-screen during Star Trek VI: The Undiscovered Country.
The most significant updates to Sulu during the TOS films, however, were the promotions he received. Sometime before the beginning of Star Trek: The Motion Picture, Sulu was promoted to Lieutenant Commander, and by The Wrath of Khan, he was a full Commander. The biggest promotion came in The Undiscovered Country, which revealed that Sulu had been made Captain and given his own ship, the USS Excelsior. Although The Undiscovered Country only explored a fraction of the Excelsior's adventures under his command, Captain Sulu would go on to make a couple more significant appearances in the franchise.
Captain Sulu In Star Trek: Voyager & Lower Decks 
After the end of the TOS films, it would be quite some time before Mr. Sulu once again appeared in the Star Trek franchise. While characters like Kirk, Spock (Leonard Nimoy), and Montgomery Scott (James Doohan) guest starred in episodes of Star Trek: The Next Generation and subsequent movies, Sulu wouldn't be seen again until Star Trek: Voyager season 3, episode 2, "Flashback". The episode not only provided some never-before-seen moments of Captain Sulu during the events of Star Trek VI: The Undiscovered Country but also connected one of Voyager's main characters to Sulu in a surprising way.
"Flashback" revealed that Voyager's Vulcan security officer, Tuvok (Tim Russ), had served under Captain Sulu on the Excelsior during The Undiscovered Country. Through a mind-meld, Tuvok and Captain Janeway (Kate Mulgrew) relived Tuvok's interactions with Sulu and his participation in a battle with the Klingons during the film. Although Sulu's scenes in "Flashback" were set during events that had already taken place in the TOS films, they did provide a closer look at what the Excelsior was like under Sulu's command, and what he was like as Captain.
