Nagisa Shiota

Pale-skinned and slender, Nagisa has long, light blue hair that reaches his shoulders and eyes to match. He is the smallest of the boys in his class and carries a distinctly androgynous look. He once tied his hair back in a single ponytail, but after Kaede Kayano styled it into twin pigtails resembling her own, the pigtails became his signature. His everyday outfit adds a dark blue vest over the school shirt, sleeves pushed up his forearms and trouser cuffs folded because of his height, with spare hair ties looped around both wrists and a yellow cardigan for colder weather. Seven years later he has cropped the hair short and, to his lasting frustration, grown barely a centimeter taller.

Nagisa is calm, approachable, and remarkably attentive, forever watching the situations unfolding around him and jotting notes on Korosensei in hopes of decoding the creature. Quieter and more timid than most of his classmates, he thinks far more than he speaks and once described himself as effectively invisible, prone to hesitation and a faint stutter that trace back in part to a mother who told him he was never good enough. Even so, threats that would rattle an ordinary person rarely shake him. Beneath the gentle surface lay a deep insecurity about his own worth and a pessimism that left him without goals and helped land him in Class 3-E, yet his year with his classmates and especially Korosensei gradually gave him confidence, perspective, and a direction of his own.

Raised by Hiromi Shiota, a mother who had wanted a daughter and controlled his life down to his long hair and forced crossdressing, Nagisa grew up under constant belittlement that eventually drove his father away. Poor grades dropped him from Class D into Class 3-E, where Kayano gave him the pigtails that began their friendship. His hidden edge surfaces almost at once: an early attempt on Korosensei, throwing himself at the teacher with a grenade at his neck, earns praise for how innocently he masked his true intent, foreshadowing the talent that defines him. Karasuma, sensing a snake-like presence behind an unremarkable student, chooses Nagisa to face the sadistic instructor Akira Takaoka in a duel with a real knife, and the boy wins by walking up with a smile and striking before his opponent can register the killing intent.

On the summer island trip Nagisa scouts underwater and, in a rematch with a vengeful Takaoka, downs him using the stun clap he had learned from the retired hitman Lovro Brovski. He fares worse against the true God of Death, who turns the same technique against him, though he recovers to see Karasuma finish the fight. His hardest battle is at home: when Hiromi tries to force him to burn down the Class E building to keep him from returning, Nagisa refuses, defeats a lurking assassin, and resolves to aim his gifts at saving and helping people rather than killing. Later, convinced the class should spare Korosensei, he clashes bitterly with his close friend Karma Akabane, and the dispute is settled by a paintball war that Nagisa wins for the save team.

When Yanagisawa and a monstrous second Reaper corner Korosensei, the class watches helplessly as Kayano is impaled, and after their teacher revives her the students accept that the time has come. Nagisa volunteers to drive the final knife into Korosensei's heart, saying a tearful goodbye as the teacher dissolves into light. Seven years on he honors that mentorship by becoming a teacher himself, taming a class of delinquents with the very skills he once trained. Those skills run deep: an uncanny knack for reading people, an ability to hold and mask his bloodlust, often pictured as a coiled viper, until the last instant, the stun clap that has felled seasoned killers, and even a kissing technique he used to subdue the tentacle-maddened Kayano.