Hiromi has been taking classical piano lessons since the age of six, and her teacher also encouraged her understanding of jazz. At twelve, she performed with an orchestra for the first time. At 14, she played with the Czech Philharmonic. At 17, she met Chick Corea and recorded an improvisation for two pianos with him. After further experience, including composing commercials for Nissan, she moved to the United States in 1999 to study at Berklee College of Music in Boston. Among her mentors at Berklee was Richard Evans, who teaches orchestration. Her debut with the Telarc record label was facilitated by Ahmad Jamal. Richard Evans co-produced her first record, which she recorded before she even graduated. It achieved gold status in Japan in 2003. In 2007, she married Japanese fashion designer Yasuhiro Mihara, and she performed live at Mihara's fashion show in Paris that same year.