short for character change. frequently used in shugo chara. its the combined power of a shugo chara (guardian character) and its owner. in most cases there is a special change in apearance and sometimes a weapon. some elements of the chara change are similar to chara nari (ikuto tsukiyomi's cat ears. hinamori amu's heart/spade/clover theme. yaya's bib). it also changes the person's personality (there character).
chara change : ikuto tsukiyomi gets cat ears and a tail plus cat-like abilities (teasing attitude). hinamori amu with miki gets artistic abilities and spade shaped barrettes (level headed attitude).