In 2006, Oka was cast as the time-manipulating Hiro Nakamura in the NBC television series "Heroes". Oka translated his own dialogue for the show, from English to Japanese; English subtitles accompanied his Japanese dialogue on the show. Prior to this, he was expecting to forgo acting by the end of that year's pilot season in lieu of pursuing writing and producing. "Heroes" turned out to be a breakout hit and his portrayal of Nakamura earned him nominations for both a Golden Globe Award for Best Supporting Actor – Series, Miniseries or Television Film and a Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series, the only actor on the show to be nominated on either award shows. He was named the "Coolest Geek" at the Spike TV Guys' Choice Awards on June 13, 2007. In 2007, he presented an award with "Heroes" co-star Hayden Panettiere on the 20th annual "Nickelodeon Kids' Choice Awards".