Max is an Orange Star CO and a protagonist in the Advance Wars series.
Before becoming a CO, Max attended the Orange Star Military Academy with Nell and Grit. He was best friends with the latter until Grit defected from Orange Star and joined Blue Moon, causing Max to develop a grudge against him for what he saw as a betrayal.
After Blue Moon invaded Orange Star, Max was sent in to assist his fellow CO Andy in repelling Blue Moon's invasion. He soon encountered Grit again, who had risen his way up to becoming the right-hand man of Blue Moon's Commander-In-Chief Olaf. Mystified as to why his former friend was working for Blue Moon now, Max was eager to face him in battle and drive back his forces.
Eventually, Max and Grit are able to reconcile after Black Hole's machinations behind the war are revealed and after Max learns that Grit only left Orange Star to resolve the love triangle between himself, Max and Nell.
Advance Wars 2: Black Hole Rising
When Black Hole returned to conquer each of the Wars World nations, Max his fellow Orange Star COs fought to repel their invasion of Orange Star spearheaded by the Black Hole CO Flak.