The Unknown Hero

I (Ava) am a 12yr old girl who lives with my dad in the wild city of New York. When I was born my mom moved out and we never saw her again. When I finally am in middle and out of primary school, my life changes drastically. I meet, a new friend Ethan (who is having the same problems), a 12yr old boy who lives with his Mum (or so I thought).
Once we fight a few monsters I find out who I really am. As for Ethan.... well you would be surprised.