Birthdate: September 3
Age: 10-12 (anime), 14 (manga)
Height: 136–140 cm
Blood type: A
Favorite subject: Mandarin, music
Least favorite subject: none
Favorite colors: light yellow, white
Favorite flowers: orchid, sakura
Favorite foods: noodles, sushi
Least favorite food: bell peppers

Tomoyo, Madison Taylor in the English dub, is the best friend of the series heroine, Sakura Kinomoto. When she discovers that Sakura has become the Cardcaptor, she becomes Sakura's primary assistant by designing "battle costumes" and filming all of her magical (and non-magical) endeavours. (The videotaping, however, seems to be more to Tomoyo's personal benefit and enjoyment than it is to Sakura's.) Tomoyo faithfully keeps Sakura's new identity secret and often covers for her in times of need.

Tomoyo is very mature for her age. One of her major character traits is her selflessness towards Sakura. Tomoyo is kind, caring, highly intelligent, beautiful, meticulous, and very melodic (she has a superb singing voice and often has solos in choir recitals). She always speaks using formal verb conjugations and expressions, giving her a unique air of refinement amongst the cast. When needed, Tomoyo can exhibit considerable cunning and resourcefulness, which was most prominently displayed in the final movie.