He studied violin and piano from early age. He enrolled at Tokyo University of Arts in 1960 and studied violin, theory and conducting and graduated with Bachelor of Music in violin.
He came to the United States in 1965 to study violin with Joseph Gingold at Indiana University. He studied conducting and minored in viola also and graduated with Master of Music in violin in 1968 and joined the St. Louis Symphony that year.
While playing with St. Louis Symphony, he helped to found Kammergild Chamber Orchestra in 1977 with Lazar Gosman and played with the group as the principal second violinist for 17 years. After that he also founded Appassionato String Quartet and played many concerts.
He has been also active in playing recitals of violin/harp duo, known as The Watanabe Duo, with his harpist wife, Ayako Watanabe. They toured in Japan in 1995, 1997 and 2005.
Haruka started to compose for violin and harp duos in 1998. The Watanabe Duo has made two CDs, the first one with the St. Louis Cathedral organist, John Romeri, the second one, with their organist son, Hideki, featuring some of Haruka’s arrangements and original compositions. The third CD with almost all his chamber music is now under preparations.
He is a member of ASCAP.
The list of compositions:
- From Sado for violin and harp, 1998
- Mélodie Mélancolique for violin and harp, 1999
- Ballade for violin and harp, 2000
- Fantasy No.3 for violin and harp, 2000
- Spring for flute (or violin) and harp, 2001
- Adagio for violin, harp and organ, (also for strings and harp), 2001
- Elegy, In Memory of September 11, 2001 for violin, harp and organ (also for strings and harp), 2001
- Fantasy for flute, oboe, strings and harp (also violin, harp and organ titled as Fantasy Trio), 2003
- Fantasy Duo for violin and piano, 2003
- Song of Shinobué for flute and harp or piano (shinobue or violin), 2003
- Concert Piece for horn and piano, 2004
- Symphonic Fantasy (Symphony in one movement), 2006
- Romantic Trio for flute, violin and harp, 2006
- Lêgende for flute, oboe, harp and strings, 2007