[1] After studying at Kwansei Gakuin University, Okoshi moved to the U.S. in 1972.

Okoshi collaborated in the 1970s with Gary Burton,[1] and played with the Mike Gibbs Orchestra at Carnegie Hall in 1974.

In the early 1990s, he played in George Russell's Living Time Orchestra and recorded with Bob Moses.

In the early 2000s he recorded several songs on the album Orpheus Again by Bruce Arnold.

[2] With Bruce Arnold With Gary Burton With Lorraine Desmarais