Eiko Tanaka is the president of Studio 4°C, an animation studio she founded with Koji Morimoto and Yoshiharu Sato in 1986. The company's name of 4°C comes from the temperature that water is at its most dense, and is a pledge of high quality work.

Tanaka is also the chief executive officer of a production company called Beyond C, which initiated the project with Michael Arias that became Tekkon Kinkreet.

Tanaka was an executive producer on Tekkon Kinkreet and Mind Game, both Studio 4°C films. She was also an animation producer on Beyond and The Second Renaissance Part 1 for the Animatrix project. Tanaka previously worked with Studio Ghibli and played the role of line producer on My Neighbor Totoro and Kiki's Delivery Service.

(Source: Wikipedia)