Their family moved to the Yonkers area of New York right after Yumi was born, due to their father's job as an interior designer.
In summer 2001, Yumi and Emi appeared on the TV audition program Asayan after sending in a demo.
[1] They released their first album, Radioactive, in 2002 under Avex Record's sublabel Cutting Edge.
On June 22, 2006, Heartsdales announced on their official website that they were going to split up to pursue new endeavors.
Yumi announced on her blog that she gave birth to her son weighing 7.7 pounds (3.5 kg) on June 25, 2010.