On Ji

"fire"

- Don't worry. I'm not a tattle tale.

On Ji is an ordinary girl who attends the Fire Nation School, and a young Fire Nation citizen. It can be inferred that, along with all her classmates at the school, she grew up in a peaceful environment, far from the war front. Her parents likely care very much about On Ji's education. It is possible that if she does well enough she might get the chance to further her studies at a good university, possibly even in the capital.

History
Aang (calling himself Kuzon) came to the Fire Nation school, saying that he was a new student from "the Colonies." After the dismissal, Aang met On Ji, who noticed Momo hiding under his shirt and warned him to keep it hidden, thinking it was a monkey. Her self-proclaimed boyfriend, Hide, seeing "Kuzon" and On Ji together, stopped by and made it clear to Aang that she was his "girlfriend" by starting a brief confrontation, during which On Ji rolled her eyes - she did not appear to be very affectionate towards Hide. Later, in band class (in which On Ji played the Erhu), Aang tried to play the Tsungi Horn and got chided by the teacher for dancing in place while playing. Nevertheless, On Ji was amused by the dance steps. When Aang offered to show her during recess, Hide became infuriated and attempted to assault Aang. Aang easily evaded Hide's attacks with quick footwork rather than striking back, an attitude derived from his Air Nomad origins. Hide eventually overbalanced and fell to the ground. Aang then got into trouble with the Headmaster for "beating up" another student.

On Ji was later invited to Aang's dance party. To get people to start dancing, Aang picked On Ji out of the crowd. She blushed, shyly took his hand, and started dancing with him, causing Sokka to comment that they looked good together (Katara expressed notable jealousy at this). When the Headmaster came to break up the party, she, along with others, put on a headband to help Aang and his crew escape. What happened to On Ji and Hide's relationship remains unknown.

It is also a matter of speculation whether she ever really had a crush on Aang. It is unknown whether she was actually Hide's girlfriend, or he was saying that just to bully Aang.

Personality
On Ji is kind and amiable with a sweet and easygoing personality. She is friendly and welcoming to others, notably Aang when he enrolls in the Fire Nation school.

Trivia

 * On Ji's hair style is the same as Chihiro's/Sen's from Miyazaki's Spirited Away. The creators of Avatar have said before that they are fans of his work.
 * Avatar Extras on The Headband say that On Ji is named after Angie, a member of the staff.
 * On Ji (Spelled Onji, 音字) is also a Japanese term; in the context of Japanese poetry, it refers to the phonetic units counted in haiku and other such poetic forms.