(1970). Takei narrated the documentary "The Japanese Sword as the Soul of the Samurai" (1969). In 1965, producer Gene Roddenberry cast Takei as astrosciences physicist Sulu in the second pilot for the original television series. When the series was accepted by NBC, Takei continued in the role of Sulu, who was now the ship's helmsman. It was intended that Sulu's role be expanded in the second season, but Takei's role in "The Green Berets" (1968) as Captain Nim, a South Vietnamese Army officer alongside John Wayne's character, took him away from "Star Trek" filming and he only appeared in half the episodes of that season. Walter Koenig as Pavel Chekov substituted for him in the other episodes. When Takei returned, the two men had to share a dressing room and a single episode script. Takei admitted in an interview that he initially felt threatened by Koenig's presence, but later grew to be friends with him as the image of the officers sharing the ship's helm panel side-by-side became iconic. Takei has since appeared in numerous television and film productions, reprising his role as Sulu in "" from 1973 to 1974, and in the first six "Star Trek" films. Today, he is a regular on the science fiction convention circuit throughout the world. He has also acted and provided voice acting for several science fiction computer games, including "Freelancer" and numerous "Star Trek" games. In 1996, in honor of the 30th anniversary of "Star Trek", he reprised his role as Captain Hikaru Sulu on an episode of "", appearing as a memory of Lt. Tuvok, who served on the under Sulu, during the events of "". Takei is one of the "Star Trek" supporting cast members whose difficulties with William Shatner have become public knowledge. However, in an interview in the 2004 DVD set for the second season of "", Takei said of Shatner: "He's just a wonderful actor who created a singular character. No one could have done Kirk the way Bill did. His energy and his determination, that's Bill. And that's also Captain Kirk." He appeared alongside Shatner on the 2006 Comedy Central "Roast of William Shatner" in which the two mocked each other in good humor and embraced, Takei noting that he was "honored" to be there "despite our past tensions". Takei is also one of six actors (the others being Jonathan Frakes, Kate Mulgrew, Michael Dorn, Avery Brooks and Majel Barrett) to lend his voice to "Star Trek: Captain's Chair", reprising his role of Captain Hikaru Sulu when users visit the bridge of the original "Enterprise" in the computer game.