Mika Todd was born in Hawaii to a native Japanese mother and American father. Her father, Johnny Todd, is a famous jazz pianist.

When she was in high school, she performed in a group with four of her friends at small resturants in Waikiki. Makoto, drummer in Tsunku's band Sharan Q saw them perform and convinced him to sign them to his Hello! Project. Mika and her group went to Japan in 1999 and became Coconuts Musume.

Soon after Coconuts Musume was created, Tsunku drafted Mika into the Morning Musume spinoff group Minimoni. Her membership in Minimoni brought her more popularity, and when founding member Yaguchi Mari left the group Mika became the new leader. Her popularity lead to her starring in the Minimoni movie, Okashi no Daiboken!.

In early 2004, it was announced that Mika would be leaving Coconuts Musume (which at this point consisted of her and Ayaka), as well as Minimoni. She graduated on 2004-05-02 and left Japan for California on 2004-05-31.