Zenitsu Agatsuma

A cowardly, perpetually wailing slayer who insists he is doomed to die on every mission, yet never abandons his comrades. Raised by a retired Thunder Breathing swordsman, he mastered only a single technique but honed it to lethal perfection. When terror finally overwhelms him he collapses unconscious, and his sleeping body fights with speed and precision he cannot manage awake.

Pale blond hair that deepens to orange toward the ends, cut in a shaggy bob, with a jagged lightning mark streaking back from the right side after he was struck by lightning in training. His large, drooping brown eyes are almost always brimming with tears, and his mouth tends to hang open in a wail. He wears the standard dark Corps uniform under a bright haori patterned with white triangles, a scale design chosen by his master. His Nichirin blade is pale yellow with a lightning bolt etched along the flat.

A coward of operatic proportions, Zenitsu panics, sobs, bargains and announces his imminent death at the slightest provocation. He is convinced he is worthless, reacts to danger by clinging to whoever is nearest, and spends an unreasonable amount of energy on hopeless declarations of love toward girls he has just met. Beneath the hysteria is a fundamentally decent person who cannot actually abandon anyone: pushed far enough, usually when a child or a friend is at risk, he stops running and fights with terrifying precision. His acute hearing lets him perceive sincerity and fear in others, which makes him unexpectedly perceptive about people even while he misreads himself completely.

Orphaned and raised without family, he was swindled into crippling debt by a woman he trusted and was found hanging around in despair by Jigoro Kuwajima, a retired Thunder Hashira. The old man cleared the debt and took him in as a disciple, demanding he learn to protect himself. Zenitsu fled training repeatedly, was tied to a tree and struck by lightning, and managed to master only the first of Thunder Breathing's forms despite years of effort. A fellow disciple scorned him constantly. His master insisted that a single technique polished to perfection was enough, and Zenitsu somehow survived Final Selection, though he remembers almost nothing of how.

1. First meeting and the Tsuzumi Mansion

   Introduced clinging to a boulder and refusing to escort children to safety, he is dragged along by Tanjiro and sent into a shifting house ruled by a drum-beating demon. Terrified past the point of consciousness, he collapses and then fights in his sleep, cutting down a demon with a single blurring strike.

2. Aftermath and the swordsmith's visit

   Awake and oblivious to what he has done, Zenitsu is given a yellow Nichirin blade decorated with lightning and reacts to his new sword and his new companions with equal panic. His infatuation with Nezuko begins the moment he realises the girl in the box is Tanjiro's sister.

3. Mount Natagumo

   Separated on the fog-shrouded mountain, he is bitten by a spider demon whose venom slowly turns victims into spiders. Resigned to death, he nonetheless protects a fellow slayer and, falling unconscious, unleashes his one perfected technique to behead the demon before the transformation can finish.

4. Rehabilitation Training

   Recovering at the Butterfly Mansion, he is poisoned, bandaged and then put through reflex and breathing drills by three young attendants who repeatedly knock him down. Motivated largely by wanting to look good in front of girls, he nevertheless learns constant Total Concentration Breathing alongside Tanjiro and Inosuke.

5. Departure on a new mission

   Cleared for duty, he leaves the mansion with Tanjiro and Inosuke, complaining the entire way about the assignment and the company. The season ends with the three of them heading toward a train line where slayers have been vanishing.

Jigoro Kuwajima

Master

The former Thunder Hashira who paid off his debt, adopted him and refused to let him quit. His insistence that one perfected technique is enough is the foundation of everything Zenitsu can do.

Tanjiro Kamado

Closest friend

The first person to tell him plainly that he has worth. Zenitsu clings to him, complains endlessly about his missions, and quietly draws courage from being trusted by someone so stubbornly kind.

Nezuko Kamado

Object of his devotion

He falls for her on sight and declares himself her protector at every opportunity, undeterred by her muzzle, her demon nature or her complete indifference to his speeches.

Inosuke Hashibira

Rival and companion

A loud, aggressive teammate who mocks him constantly and whom he insults right back. The two bicker through every mission yet fight on the same side without ever being asked twice.

• He is first found clinging to a rock, refusing to move while children wait to be escorted to safety.
• He faints from terror inside the drum demon's mansion and kills a demon in a single unconscious strike.
• He receives a yellow Nichirin blade engraved with a lightning pattern.
• Bitten and slowly turning into a spider, he beheads the demon responsible rather than abandoning a fellow slayer.
• He masters constant Total Concentration Breathing during rehabilitation training, largely to impress the girls teaching him.

• The lightning streak in his hair dates from being struck while tied to a tree during training.
• He can only perform the first of Thunder Breathing's six forms.
• His triangular scale-patterned haori was chosen for him by his master.
• His hearing is sharp enough to recognise people by the sound of their bodies and to tell when they are lying.
• He insists he is about to die with such regularity that his companions have stopped reacting.

• Tanjiro Kamado
• Nezuko Kamado
• Inosuke Hashibira
• Giyu Tomioka

Back to the Demon Slayer: Kimetsu no Yaiba guide