Naoya is a tall and slim man with brown eyes and dyed blond hair accented with his dark green roots. He almost always has an arrogant grin plastered across his face and believes himself to have an appearance befitting a clan head, implying he's much better looking than other members like Jinichi. He has four earrings in and on his left ear, two studs along the lobe, and two cuffs along the helix. In the manga, he has two more earrings in his right ear, two studs along the lobe. Naoya wears a traditional attire that resembles most of his clan members. He sports a white long-sleeved shirt that buttons the color underneath his teal kimono. He completes his outfit with light-colored hakama and waraji sandals, paired with dark-colored tabi socks. When Maki was massacring the Zenin clan, Naoya is seen wearing dark-colored hakama with light-colored tabi socks. From a young age, Naoya was always praised and told by others that he was a genius. He was severely spoiled as the youngest and most promising of Naobito's children. He was conditioned to view himself as his father's successor and as a result, Naoya's arrogance grew to unbridled levels even as a small child. He looked down on all those he views as weaker than him, which is the vast majority of the people Naoya came across. The only person Naoya ever appeared to have any respect for was Toji. He went to visit him as a child to mock the pitiful man without cursed energy but was instantly able to recognize Toji was extremely strong in spite of that. This led Naoya to embrace the ideology that the sin of the insignificant is the ignorance of true strength. Naoya felt he was one of the only ones who understood Toji and strived to be as exceptional as he was. Naoya confidently pursued strength to the point where he viewed everyone else as inferior to himself. He refused to acknowledge anyone's talent, referring to his elders, Jinichi and Ogi, as weaklings despite their experience as senior members of the clan. Naoya's reckless and conceited attitude irritates even his fellow clansmen, to the point where Ogi and Jinichi attacked him for being excessively pompous. Raised in an environment that breeds superiority, Naoya developed several sociopathic and narcissistic tendencies and strongly embodied all the stigma about the Zenin clan. He has no family values whatsoever other than trying to outdo everyone to become head of the clan. He didn't express any amount of concern for Naobito, his father, on his death bed and has said more than once that he hates all his older brothers as well. Naoya is openly misogynistic, viewing women only as wives and casually telling Mai's mother that a woman who can't walk three paces behind a man should be stabbed in the back.