In 1979, he formed a jazz rock band with some of Japan's leading studio musicians, and recorded the album Kylyn.

[5] In the 1980s, he toured as guest soloist with Steps, the Brecker Brothers, and Word of Mouth, led by Jaco Pastorius.

Watanabe created the jazz-rock/jazz-fusion band Mobo in 1983 with Mitsuru Sawamura (saxophone), Ichiko Hashimoto (piano), Gregg Lee (bass), Shuichi Murakami (drums), and Kiyohiko Senba.

A DVD was issued from the tour which featured drummer Bill Bruford and bassist Jeff Berlin, who also played on the record.

In the 1990s Kazumi assembled an all-Japanese line-up called Resonance Vox (Vagabonde Suzuki on bass, Rikiya Higashihara on drums, Yahiro Tomohiro on percussion).