Eichi Matsuoka emerges as a formidable external rival to the protagonist, his calculated confrontations amplifying tensions that ripple through the narrative. A pivotal turning point arrives in episode 4 when critical injuries force his abrupt withdrawal from direct antagonism. This absence creates a power vacuum, swiftly exploited by ambitious younger delinquents eager to cement their dominance through escalating clashes. Though sidelined, his influence lingers indirectly as fresh rivalries ignite, reshaping the story’s conflicts without further elaboration on his past or future endeavors.