guardian chara
Tiny fairies born from the "egg" of a child's heart in Shugo Chara!, also known as the "Heart's Egg". Sometimes, a strong emotion can trigger the egg to hatch into a Guardian Chara in order to aid that person in becoming his or her would-be self and pursue his or her dreams. If the egg gets corrupted, it may turn into an X-Egg.
These creatures are invisible to normal people, and only owners of Guardian Charas and pure-hearted children can see them.
When owners of Guardian Charas character transform with them, they turn into their "would-be-selves."
