Gi | Captain Planet and the Planeteers Wiki:

Gi never reveals what Asiatic country she is from. She does, however, have friends from Thailand (Nuok), whom she met through school, as learned in the episode Beast of the Temple. She has been shown as able to read both languages: Mandarin Chinese and Japanese, and it was later revealed by Barbara Pyle herself that Gi was based upon a Malaysian activist, although she was made to represent all East and South Asians. Gi's dolphin friend's name was named Kisa, as learned in the episode A Mine is a Terrible Thing to Waste Part II, and this name has roots in Japanese culture. The name 'Gi' is Korean, but is a predominantly male one, hence she is often assumed to be Korean by fans.