How does the main character react to the challenges he faces in The Absolutely True Diary of a Part-Time Indian?

Junior's response throughout the narrative is to not take
the form of the world around him.  This becomes the manner in which Junior responds to
the pressures that face him.  For example, when confronted with not having adequate
textbooks, Junior does not simply accept this reality like others before and with him. 
He rebels, distinctly taking a form that is not like the world around him.  His cartoons
are another way in which he faces challenges by remaining distinct from the world that
challenges him so much.  At Reardon, he does not succumb to the pressures of being the
lone Indian in a White world.  Rather, he accepts who he is and does not capitulate to
the world around him by surrendering his identity.  He fights, and perseveres by
assuming a distinct level from what is enveloping him.  Junior maintains his voice,
which becomes the primary coping mechanism for him to deal with the challenges that face
him.  This is even applied to his personal life, where he recognizes the challenges with
his father and does not reject him.  Yet, Junior remains committed to his identity and
with this in hand emotionally appropriates his father recognizing his
limitations.