She is later introduced as an optional character, as such she does not appear in the ending FMV. Her most distinguishable trait is her humor and her outgoing personality. Yuffie gives almost everyone in the party derogatory nicknames, (Tifa-Boobs, Cid- Cranky-legged Old Man, Cloud- Spikes). But for Aerith, who Yuffie holds a high respect for, she does not and when the flower girl was killed Yuffie cried uncontrollably and hugged Cloud. This is an example of Yuffie's kindness.
Yuffie is one of the characters in the Compilation of Final Fantasy VII that has more than two costumes.
Yuffie has a very interesting obsession with Materia. Having tried to steal from the party many times. The reason for this is that Materia was banned in Wutai, which is where Yuffie is from, and in order to restore Wutai to it's former glory, Yuffie wanted to bring Materia back into her homeland.
In the end, Yuffie is not only a valuable addition to the party but a source of comic relief. ~