Firebreather (2010) on Netflix

Plot summary

Sixteen years after the war between humans and the Kaiju, Duncan Rosenblatt and his mother Margaret move into a new house so he can start at a new school. Duncan has his father's Kaiju look and powers, and he fears other students will single him out for them. At school he falls for Jenna and makes an enemy of her ex-boyfriend Troy, and he befriends two outcasts, Kenny and Isabel. After Duncan breathes fire, Barnes, an agent posing as a gym teacher, brings him to Dr. Pytel at the M.E.G.T.A.F. base. His father Belloc, king of all the Kaiju, comes for him and wants him to succeed him as ruler.