He is officially handsome. Even Pizza Nakajima, who attacked Sakamoto's shop, referred to Nagumo as a 'handsome man.' During his time at JCC, he received 152 chocolate gifts from female students on Valentine's Day, requiring a cart to haul them away. Furthermore, when asked how the characters would live if they hadn't become killers, author Yuto Suzuki replied that Nagumo would likely be a model or an actor, drifting through the entertainment industry, confirming his status as a canonical beauty. He generally has a very sly and playful personality, which he displays toward allies and enemies alike. Because of this, he teased Shin and Lu by disguising himself as Sakamoto upon his first appearance, lied about his age and personal details, and was scolded three times by them after playing a prank where he 'killed' Shin with a toy knife at the Donden-kai massacre site. He seems to get along—or perhaps just clash—with the eccentric Osaragi. As a killer who stood shoulder-to-shoulder with the legendary Taro Sakamoto, he possesses strength that ranks him 1st or 2nd even within the ORDER. During the Death Row Convict arc, the X faction assigned him an S-rank. He toyed with Minimalist—a man who kills by compressing people with raw strength—using tricks and speed, and even overpowered him in physical strength, subduing him by the throat with one hand. His victory against Gaku, an ORDER-level fighter from Slur's faction, and his combat scenes in flashbacks prove he is an overwhelming powerhouse. For this reason, Oki, the current leader of the ORDER, seriously considered Nagumo as his successor.