A crucial piece of Mr. Sulu's (George Takei) backstory was planned for Star Trek IV: The Voyage Home, but the scene was never finished and was sadly cut from the film. Takei portrayed Hikaru Sulu, the helmsman of the USS Enterprise, in Star Trek: The Original Series, Star Trek: The Animated Series, and all six Star Trek movies starring the TOS cast. But Star Trek IV's moment meant to shed light on Sulu's origins was lost.
In Star Trek IV: The Voyage Home, Sulu's role was perfunctory and similar to his tasks in the previous Star Trek movies: sit at the helm of the Klingon Bird-of-Prey stolen by Admiral James T. Kirk (William Shatner) and pilot it as he did the Starship Enterprise. Sulu flew the Klingon warbird, nicknamed the S.S. Bounty, back in time to 1986 so that Kirk and his crew could exact their crazy plan to find two humpback whales and bring them back to save the Earth in the 23rd century. Sulu joined his crew on their excursion in San Francisco, but Takei didn't get to enjoy the spotlight moment intended for Sulu.
Why Star Trek IV Cut Sulu's Backstory
Star Trek IV: The Voyage Home's screenplay originally included a scene where Mr. Sulu would run into a young boy in 1986 San Francisco who he realized was his great-great-great grandfather. George Takei was delighted at the inclusion of this scene. However, when it became time to film Sulu meeting his ancestor, the young boy hired for the part had difficulty performing, and his domineering mother on set made things even worse. Unable to film the scene, the production chose to scrap it and move on, to Takei's heartbreak. Takei wrote about this disappointment in his 1994 memoir, To The Stars: The Autobiography of George Takei, as did William Shatner in his 1994 memoir, Star Trek Movie Memories.
Ultimately, the scene of Mr. Sulu meeting his 20th-century ancestor could be cut from Star Trek IV because, while it was a nice moment for the Enterprise's helmsman, it didn't move the Star Trek IV's story forward. Sulu's later moment of 'borrowing' a helicopter to transport transparent aluminum to the Klingon Bird-of-Prey to build a holding chamber for the whales was more pivotal to the story. But George Takei was still understandably disappointed because Sulu's backstory had never been touched upon in Star Trek before. All that remains in the film is Sulu noting "I was born here" when Kirk and his crew arrive in San Francisco.
George Takei Got His Wish When Sulu Became Captain In Star Trek VI
In Star Trek V: The Final Frontier, Mr. Sulu was back at his post flying the USS Enterprise-A, and he had little impact on the story of Sybok's (Lawrence Luckinbill) mad quest to meet God. But Star Trek VI: The Undiscovered Country marked a pivotal turning point for George Takei and Mr. Sulu, who was finally promoted to Captain and was in command of the USS Excelsior. Although he was removed from the main action aboard the Enterprise, Sulu as Captain of his own starship was a long-awaited leveling up for Takei's iconic character. Sulu and the Excelsior were also pivotal in helping Captain Kirk and the Enterprise save the galaxy one final time.
Captain Sulu has had a bit more canonical character development and backstory reveals since Star Trek IV. Star Trek Generations introduced Hikaru's daughter, Ensign Demora Sulu (Jacqueline Kim), who was a chip off the old block as the helmsman of the USS Enterprise-B. Captain Sulu also appeared in Star Trek: Voyager, and Takei voiced Sulu's comeback in Star Trek: Lower Decks. The disappointment of Sulu not meeting his ancestor in Star Trek IV: The Voyage Home hasn't impeded the icon's legend one bit.