Yonekura was born in Yokohama. She studied classical ballet for 15 years from the age of five. A member of the Oscar Productions agency, she won a national young beauty award in 1992. In 1993 she started her career as a model, working for fashion magazines such as CanCam. She announced her intention to start her acting career in June 1999. Her acting debut was in the TBS drama Koi no Kamisama (God of Love) and has appeared in many dramas ever since.