Okada was originally involved with the Mega Man X series of games, starting with X5 as an aide to Takuya Miyawaki (prior to his employment), then as a sub-composer for X7 (followed later by X8 and Maverick Hunter X) and finally as main composer for Command Mission, the series' RPG-spinoff. He would then co-compose Haunting Ground, Monster Hunter 2 and Zack & Wiki: Quest for Barbaros' Treasure. As of 2009, however, Okada has shifted to a sound managerial role, usually as an assistant to lead sound manager Mitsuhiko Takano (and formerly Tetsuya Shibata).