Yunior is the narrator of the book "The Brief Wondrous Life of Oscar Wao" and is also Oscar's friend and former roommate. Their relationship is a mix of admiration, frustration, and disappointment. Yunior admires Oscar but is also frustrated by his lack of success and self-destructive behavior. Despite these frustrations, Yunior remains loyal to Oscar and cares deeply about him, trying to understand and tell his story.