What is the relationship between Rowdy and Arnold when he still goes to school on the reservation?Can you explain it to me, I'm really confused.

Rowdy and Junior(Arnold) are best friends, but at certain
times this relationship is almost hidden. Perhaps this is why confusion has arisen for
you. Rowdy is super tough. Junior is a completely awkward nerd. These two characters
should not mix. Being best friends doesn't fit. But when no one is looking, Rowdy is
totally capable of being as dorky as Junior and this is what makes their relationship
thrive. Additionally, Rowdy will defend Junior at any opportunity he gets. In fact, it
is almost as if Rowdy enjoys being violent, particularly on behalf of Junior. Many
people try to bully Junior and this is part of where Rowdy gets opportunities to vent
his frustrations on humanity.

Now, when Junior goes to the
white school, their relationship changes forever as Rowdy feels slighted by
Junior.