Pan's psycho warrior

Calina a girl with a tuff childhood born in the streets and left alone, taken to an orphanage only to escape at the age of 13, she lives on the streets alone anywhere she can the forest , the town, anywhere...... But what happens when one day she hears a mysterious pipe? Follows the sound only to come across a boy who seems to be the boy version of her , the only thing is she has a BIG secret. What will it be ? Who is this boy? Who is she? What will happen next?......