Yoko is a light gray cat with three whiskers on each side of her cheeks. On the top of her head, she has three gray stripes that are the same color as her tail markings. She has green eyes, a light pink nose, and pale pink markings inside her ears.
Yoko usually wears a yellow dress with a red jacket on top of it. The collar of her dress sticks out from the top and at the center of her jacket is a peach strip with white buttons on it.
She can also be seen in a pale pink leotard with a pink bow and slippers.
Yoko is a friendly and sweet girl who was originally from Japan. She plays the violin well and sees the best in people. Yoko enjoys many aspects of Japanese culture, including sushi and origami, which has occasionally caused problems for her and her classmates. She appears to be withdrawn and somewhat delicate in comparison to the other children. While she's willing to try new things and gets along well with them, she struggles when it comes to showing others her special talents or things related to her culture out of concern, and they will laugh at her or just treat her differently.
- Yoko will appear with Timothy and friends as NPCs in ToonWorld All-Stars Online.
- Yoko seems to have been the main character in Rosemary Wells' books. She has the most written about her, including: Yoko, Yoko Writes Her Name, Yoko's Paper Cranes, and Yoko's World of Kindness.