Born and raised in Japan, she moved to London and studied at the London Studio Centre. Upon graduation Soonja joined Ballet Ireland’s Sleeping Beauty tour and joined Scottish Ballet under the direction of Ashley Page. She danced many principal roles with the company, including both Cinderella and Aurora in Ashley Page’s critically acclaimed production of Cinderella and Sleeping Beauty. She also performed in many other principal roles by choreographers including George Balanchine, William Forsythe, Frederick Ashton, Trisha Brown and Krzysztof Pastor.
Soonja became a freelance dancer after leaving the Scottish Ballet, before going on to study with the British Ballet Organisation to become a qualified teacher.