Born in Tokyo,[1] she started ballet at age three after seeing Swan Lake on television.
She won the first prize at the International Competition of Vignale Danza in 1998.
Following artistic director Wayne Eagling's departure, she auditioned for The Royal Ballet in London.
[2] In 2018, Kobayashi retired from The Royal Ballet after 15 years in the company.
[1] Kobayashi is married to Federico Bonelli, a principal dancer at The Royal Ballet, whom she met in Zürich.