Nagumo is an old friend of Sakamoto. He is a member of "The Order", a group of assassin who're the highest ranked in the Dondenkai. He's first seen paying a visit to Sakamoto to inform him of his bounty.
Nagumo is a tall man with short neck length black hair. He has large dark eyes. On the left side of his neck he has a marking of the Fibonacci Spiral. He also has markings on his hands, they appear to be numbers or symbols. He is mostly seen wearing a polo with a large trench coat as well as black pants (presumably slacks) and formal shoes. He carries a long briefcase around his back in which it contains his long, unusual, swiss-army-knifelike weapon.
Nagumo is always seen smiling, and always seems to have a happy and laidback attitude no matter the situation. He is cheerful even when standing in a room full of dead bodies. He also doesn't flinch at the sight of blood or death, as expected of an assassin.
Abilities and Powers
Enhanced Speed and Reflexes: Nagumo is capable to move at blinding speeds, being fast enough to momentarily disappear. He can move so quickly that he managed to catch even Shin, a trained assassin and psychic, off-guard.
Enhanced Strength: Nagumo is surprisingly strong, especially for someone his build. He was able to lift Minimalist, a huge man feared for his insane strength, by choking him on the neck.
Hitman Skills: As a member of the Order, Nagumo is an extremely powerful hitman. He was regarded as S rank in the hitlist given to the death row inmates, which gives an idea as to how skilled and dangerous Nagumo is.
Mimicry: Nagumo has the unique ability to copy other people's appearances, which he used to fool Liu Xiaotang by disguising as Sakamoto.