Nagumo is a highly skilled and enigmatic hitman in the manga and anime series 'Sakamoto Days.' Known for his laid-back attitude and sly smile, he is a member of the Order, an elite group of assassins. Despite his playful demeanor, Nagumo is extremely dangerous and capable, using a variety of disguises and weapons in combat. He has a mysterious past and often acts as an unpredictable ally or adversary to the protagonist, Sakamoto, adding depth and tension to the story.