When singer and keyboardist Neal Morse was in the band, Ryo played Hammond organ and Mellotron on the albums.

Since Morse's departure, Okumoto has played all of the band's keyboard parts.

Aside from his work with Spock's Beard, Okumoto has performed and recorded with numerous other artists and groups, including GPS, K², Phil Collins, Eric Clapton, and Asia featuring John Payne.

For three weeks in 1998, Okumoto was a member of Eric Burdon & the New Animals, before being replaced by Martin Gerschwitz.

[2] In 2019, Ryo joined the progressive rock supergroup cover band, ProgJect.