the physical demands force most of them to retire in their 30s, but japanese ballerina yoko morishita is still at it at the age of 64. keiko kitagawa has her story. ♪ >> reporter: yoko morishita is the driving force of japanese ballet. more than three decades of becoming the first japanese to perform at the paris opera prima ballerina more than 30 as times a year. her entire life is centered on ballet and her daily five-hour class. when you're practicing, is there something you try to keep in mind, a motto, so to speak? >> translator: if there's something i'm not satisfied with, the next day i try to approach it differently. i take each day with a fresh start like a first grader at elementary school. >> reporter: morishita was born in hiroshima in 1948. she was a sickly child. her doctor recommended exercise at the age of 3, so she began studying ballet. her decision to become a professional dancer came when she was 12. she moved to tokyo by herself and enrolled in a famous ballet school. day in and day out, she underwent rigorous training. the big turning point in her life came at th