Yoko Kawaguchi was born in Nagasaki, Japan. She started classical piano at age five.

Yoko later studied at the University of Wisconsin on a Japanese Ministry of Education grant. She then went on to study jazz with the legendary jazz great and innovator Dr. David Baker at Indiana University, where she received a Master's degree in Jazz Studies.

Yoko performed her original works regularly in her own Sextet as well as in various groups, including Salsa Ensemble and String Jazz Quartet. She is the 1999 recipient of the Mack H. Kay Scholarship for Excellence in Jazz Composition. After arriving in New York, she joined the Barry Harris workshops.

In 2005, Yoko self-produced her debut recording "Before It's Too Late", played with bassist Earl May and drummer Leroy Williams. It was reviewed with: "shows the young Japanese woman as a first-class piano player, composer and arranger". "Kawaguchi's original compositions stand up to repeated listening".

She has performed extensively in many jazz clubs throughout New York and on the East Coast.