Oka first tried acting in 2000. He earned a Screen Actors Guild card by appearing in industry films, then moved to Los Angeles. ILM stipulated in his contract that he could work at its Los Angeles branch but would have to return to their Marin County location if he did not get cast for a recurring role that season. Oka later got cast on a pilot. Although the show was not picked up, it did satisfy the contract's requirements and he was allowed to stay in Los Angeles.