Nagumo is exceptionally handsome; during his time at JCC, he received 152 chocolate gifts from female students on Valentine's Day, requiring a cart to haul them away in boxes. His eyes are notably round. While his overall features are quite youthful and many find his smiling expression cute, the chilling look he gives when facing an enemy or when extremely angry is so terrifying it's hard to believe he's the same person. He has many tattoos all over his body. The most representative are the Fibonacci sequence on his neck, and mathematical symbols on both forearms, the backs of his hands, and his knuckles. In addition, foreign quotes, various geometric shapes, birds, and snakes are engraved. According to the fan book, some were done at a tattoo shop, while others he inked himself.