When schools become war zones and both sides start taking casualties, what then?

Brooklyn High school teacher Trevor Garfield is repeatedly stabbed by a student. Fifteen months later, moves to Los Angeles to the unruly, predominantly Indigenous Latin American area. His new school is full of dangerously, undisciplined four Indigenous Latino American students and one European-American student who are a part of a tagging gang called, K.O.S. (Kappin' Off Suckers).