TV-Series
Description
Osomatsu Matsuno stands as the eldest of six identical sextuplet brothers. Childhood portrayals consistently show him asserting leadership, marked by a fiery, self-confident, and pushy nature. He frequently initiated schemes and mischief, displaying gluttony, greed for money, and occasional cruelty towards weaker individuals. Despite this, moments of vulnerability or remorse surfaced, like guilt after abandoning his family for adoption promises or shaving his head in repentance for causing trouble. Key childhood traits included chronic dental issues, bedwetting, and a hatred of green peppers. He commonly antagonized characters such as Chibita and Iyami, with their conflicts ranging from rivalry to uneasy alliances.

As an adult, Osomatsu retains his self-proclaimed leadership role but embodies a lazy NEET lifestyle coupled with what his profile terms a "sixth-grader's mentality." He developed a heavy addiction to gambling, especially pachinko and horse racing, often stealing his brothers' savings to fund it and reacting violently to losses. His personality blends a laid-back, unmotivated attitude with shameless acts—like making lewd remarks or stalking love interests—alongside occasional, often ineffective, concern for his brothers. He openly resents being a sextuplet yet feels a contradictory responsibility toward his siblings, though his actions frequently sabotage them. Physically, he is distinguished by red-tinted hair and frequently wears red clothing, featuring a wide, toothy grin and a nose more upturned than in childhood designs.

His relationships with his brothers involve constant friction; he alternates between undermining them for personal gain and relying on them for companionship. Group dynamics reveal collective traits like anxiety about adulthood, jealousy of others' success, and inappropriate interactions with women. Osomatsu shares these flaws, exhibiting extreme awkwardness around women and covering his crotch when they pass. Despite their conflicts, the brothers show mutual, dysfunctional dependency, with Osomatsu labeling them his "five enemies" while acknowledging their irreplaceable bond.

Across films, OVAs, and spin-offs like *Matsu Inu*, his core traits remain consistent. Theatrical releases and specials, such as *The Soul's Takoyaki Party*, depict no substantive growth, reinforcing his stagnant NEET lifestyle. Alternate timelines, like one where he becomes obese, similarly reflect his inability to escape his flaws. Flashbacks to his teenage years show minimal change, with behaviors like public harassment of girls persisting into adulthood.

Osomatsu's self-consciousness manifests as a small, dented red ball in one episode exploring the brothers' psyches. This symbolizes his manageable but neglected inner self, contrasting with his brothers' more pronounced insecurities. His occasional softer moments—such as fleeting guilt over his brothers' struggles—rarely lead to lasting change, cementing his role as a static character whose development is hindered by fear of maturity and failure.