A girl who born on a thunderous and stormy night. Ronja is the only daughter of the robber chieftain Mattis, from whom she has gotten her energetic and reckless demeanor. She's quick-tempered and rash, but is very affectionate and honest about her feelings. She loves her mother and father and all of the Mattis robbers.

She loves to spend her time in The Woods, and in time, learned the things she has to know in order to survive in the forest.

She later meets with Birk and their relationship became aching like that of a brother and sister.
She faces Mattis after he kidnaps Birk, and gives herself to Borka's robbers as a hostage in order to release Birk from her father.