who are the other main characters in the movie?
Anna, Elsa and Kristoff
Anna (Frozen)
The original character of Gerda, known as Anna, was one of the three major characters in the script at this time, along with the Snow Queen, Elsa and Kristoff, 
who does the voice for anna in frozen Kristen Bell
wiki:18716997
Anna (Frozen) [SEP] Origins and conception
The original character of Gerda, known as Anna, was one of the three major characters in the script at this time, along with the Snow Queen, Elsa and Kristoff, loosely based on Kay. The characters were not considered to be well-rounded or relatable, but an interpersonal, family dynamic was created once Anna and Elsa were established as sisters, an idea suggested by someone on the writing team that no one remembered who. This changed the story dramatically, shifting from the conflict between the good and the evil to the conflict between love and fear. Buck stated that their script still retained basic parts of the story and the character of Gerda, citing the similarities between the original story and his version, "[Gerda] won't give up on finding her friend Kai.