Osamu Fukuzawa is a Japanese pianist, keyboardist, and arranger active as a support musician in the country's live and studio music scene. Known for his versatile playing style and ability to adapt across genres, he has supported various artists in concert settings, bringing both technical skill and expressive depth to his performances.

In 2025, Osamu Fukuzawa joined ONE OK ROCK as a live support member on piano, stepping in to replace Gakushi during the ONE OK ROCK DETOX JAPAN TOUR 2025. His role was highlighted during the band's monumental concert at Nissan Stadium in Yokohama, where his piano accompaniment added dynamic depth to ONE OK ROCK's large-scale stadium sound.