Sumi Tonooka was born in Philadelphia, Pennsylvania on October 3, 1956. She began studying classical music at an early age and because her mother was a huge jazz fan, Sumi also began listening to the music of Monk, Billie Holiday, Bird and Fats Waller. At the age of 15 Sumi left Philadelphia for the City of Boston with the intention of enrolling at the Berklee School of Music or the New England Conservatory. Once there, however, she found school hot to her liking and chose instead to study privately with Charlie Banacus and Madame Margaret Chaloff, mother of baritone saxophonist, Serge Chaloff.
After leaving Boston, Sumi spent a short time in Detroit performing with trumpeter Marcus Belgrave before returning to Philadelphia. After her return, Sumi enrolled in the Philadelphia College of the Arts and began studying privately with the French pianist, Bernard Peiffer. During the same period, she also began weekly trips to New York to study with Mary Lou Williams.
During the mid-70s Sumi began working around Philadelphia with the late "Philly" Joe Jones. This was her first gig of real importance. Most of the 70s and 80s were spent studying and performing in and around Philadelphia. In addition to studying piano, Sumi began to study composition in earnest with people like Don Sebesky and Dennis Sandale. It soon became apparent that she had a gift for composition. Her endeavors began to pay off in the late 80s when she began receiving commissions for large ensembles, film and dance.
In addition to performing and composing, Sumi is also on the faculty at Rutgers University in New Jersey where she teaches jazz composition and arranging.