Zenitsu

Biodata

Feature	Value
Name	Zenitsu Agatsuma (善逸) 70
Alias(es)	Sleep Hashira; Blondie 90 164
Gender	Male
Affiliation	Demon Slayer Corps; disciple of Jigoro Kuwajima; Tsugikuni Kuuga's successor 70 151
Occupation/Role	Demon Slayer and Thunder Breathing swordsman 90 180
Status	Alive 180
First Appearance	Chapter 70

Power Progression

Stage / Realm / Level	Chapter	Notes
Instinctive lightning-speed movement	70	While fleeing Inosuke on Mt. Peach, Zenitsu reacts with a golden flash of speed without conscious intent.
Thunder Breathing, First Form: Thunderclap and Flash	90	After fainting in the Demon's House, he unconsciously draws and beheads the Long-Tongued Demon.
Thunderclap and Flash: Sixfold	97	While poisoned by Spider Brother, Zenitsu commits to fighting and uses a sixfold burst to decapitate him.
God Speed	117	He identifies God Speed as a technique normally limited to two consecutive uses; this instance occurs within Enmu's dream.
Third God Speed	138	Zenitsu states that his third God Speed is his limit while joining Tanjiro against Gyutaro.
Expanded God Speed and Eight Consecutive	150	Against Hantengu, he links four God Speed activations—beyond his normal three-per-day limit—and destroys the demon's pots, badly damaging his legs in the process.
Conscious Thunder Breathing	179	Hashira Training and Jigoro's letter allow Zenitsu to perform sword techniques without needing to fall asleep.
Thunder Breathing, Seventh Form: Fire God	180	He uses an extreme-speed slash to behead Rui during the Infinity Castle battle.

Background

Zenitsu trained under Jigoro Kuwajima on Mt. Peach. He was terrified of training, repeatedly climbed a tree to avoid it, and had not participated in Final Selection when Tsugikuni Kuuga first met him. Despite this, his instinctive burst of speed impressed Kuuga, who assured Jigoro that Zenitsu would eventually shine like lightning. 70

Kuuga's encouragement became pivotal to Zenitsu. Told that concentrating even a single form at one point could reach the peak, Zenitsu resolved to become strong enough to earn recognition. 71 He continues to seek validation from his master, Kuuga, and his companions, especially after the death of Jigoro's elder disciple. 151 179

Appearance

Zenitsu is a blond-haired swordsman whose fearfulness is often visibly expressed through tears, trembling, and frantic attempts to flee. 70 97

• Golden-yellow hair. 70
• Wields a Nichirin Blade. 90
• Wears a yellow haori; during Fire God, it burns away into airborne flame. 180

Personality

Zenitsu is deeply fearful of demons, pain, and harsh training. He frequently cries, faints, complains, and attempts to escape, even when his friends are in danger. 89 107 171 He is conscious of these faults and openly hates his past self for being weak, cowardly, and prone to running away. 97

Beneath his panic, Zenitsu is compassionate and protective. He confronts Daki after witnessing her abuse a young girl despite immediately recognizing her as an Upper Rank demon. 132 His affection for Nezuko repeatedly motivates him to overcome fear, endure training, and fight beyond his limits. 94 164 172

He craves affirmation from people he respects. Kuuga's praise gives him confidence after the Demon's House mission, while Tanjiro's recognition pushes him to resume training voluntarily. 91 167 When asleep or fully focused in battle, Zenitsu becomes calm, decisive, and remarkably reliable. 90 138 180

Abilities & Skills

Thunder Breathing

Zenitsu specializes in high-speed sword-draw attacks, concentrating his strength into explosive linear movement.

• Uses Thunderclap and Flash to instantly close distance and decapitate enemies. 90
• Can enhance the First Form into Sixfold and Eight Consecutive attacks. 97 150
• Developed or attained the Seventh Form, Fire God, which he uses to kill Rui before the demon can perceive his movement. 180
• Initially relies on an unconscious state to access his full ability, but can consciously use his sword techniques after Hashira Training. 90 179

God Speed

God Speed is Zenitsu's most demanding acceleration technique, granting speed sufficient to evade, intercept, or destroy attacks that ordinary swordsmanship cannot answer.

• Severs Rui's spiderwebs during the Infinity Castle battle. 180
• Lets him destroy Hantengu's octopus pots and break through encirclement. 150
• Was normally limited to three uses per day; forcing a fourth activation cracks the skin of his calves and ankles. 150
• Zenitsu identifies a third activation as his limit during the battle with Gyutaro. 138

Exceptional Hearing

Zenitsu's hearing allows him to notice threats and details others may miss.

• Detects the Long-Tongued Demon behind him despite facing away from it. 90
• Immediately recognizes Daki as a demon—and likely an Upper Rank—despite her human disguise. 132
• Overhears Obanai Iguro's quiet comments during training. 166

Unconscious Combat State

When Zenitsu faints, his demeanor changes from panicked to composed and lethal.

• While asleep, he calmly defeats the Long-Tongued Demon with Thunderclap and Flash. 90
• Protects Nezuko and train passengers from Enmu's flesh tentacles while unconscious. 119
• Remains level-headed while using Third God Speed against Gyutaro. 138
• This dependence is eventually overcome through rigorous training and renewed resolve. 179

Equipment / Weapons / Items

• Nichirin Blade — Zenitsu's primary demon-slaying weapon. 90
• Yellow haori — Worn during the Infinity Castle battle; burns away during the Seventh Form, Fire God. 180

Relationships

• Jigoro Kuwajima — Master and guardian. Jigoro remains strict but patient with Zenitsu, and his encouraging letter later strengthens Zenitsu's resolve to train and survive. 70 179
• Tsugikuni Kuuga — Mentor and benefactor. Kuuga recognizes Zenitsu's potential, subjects him to difficult practical training, and later calls him an excellent successor. 71 89 151
• Tanjiro Kamado — Close companion. Tanjiro repeatedly encourages Zenitsu, trusts his combat ability, and helps restore his confidence after harsh training. 97 167
• Nezuko Kamado — Zenitsu's primary romantic motivation. His desire to protect and impress her drives him into missions and training he would otherwise avoid. 94 164 172
• Inosuke Hashibira — Rival and frequent source of chaos. Inosuke's pursuit first triggers Zenitsu's instinctive speed, and the two continually compete during training. 70 164
• Siegfried — A child Zenitsu is assigned to protect in the Demon's House. Siegfried harshly challenges Zenitsu's cowardice, then later witnesses and confirms his strength. 89 91
• Chuntaro — Zenitsu's sparrow companion, who pushes him to enter Mount Natagumo despite his fear. 94
• Obanai Iguro — A harsh training instructor who chases, cuts, and ties Zenitsu to a pillar after Zenitsu mocks his feelings for Mitsuri. 166

Story Role / Major Arcs

Mt. Peach

Zenitsu is introduced avoiding Jigoro's training from a tree. His instinctive speed appears when Inosuke chases him, and Kuuga's praise gives him the confidence to believe in his own potential. 70 71

Demon's House

Kuuga brings Zenitsu to the Demon's House as a trial. Terrified and unwilling to fight, Zenitsu faints when confronted by the Long-Tongued Demon; his sleeping self then kills it with Thunder Breathing. The victory gives him his first real confidence in his strength. 89 90 91

Mount Natagumo

Zenitsu enters Mount Natagumo because Nezuko is inside. Poisoned by Spider Brother, he reflects on his weakness, chooses to fight, and decapitates the demon using Thunderclap and Flash: Sixfold. 94 97

Mugen Train

While asleep, Zenitsu protects Nezuko and train passengers from Enmu's tentacles with Thunder Breathing. His speed helps keep all two hundred passengers unharmed. 119

Entertainment District

Zenitsu enters Kyogokuya to search for Hinatsuru. He identifies Daki's true nature and defends an abused girl despite his fear, but Daki knocks him unconscious. He later rescues Nezuko from Gyutaro and uses Third God Speed in the ensuing battle. 132 136 138

Swordsmith Village

Zenitsu confronts Upper Rank Five Hantengu alone. He repeatedly uses God Speed to destroy the demon's pot-based attacks, pushes himself past his normal limit, and suffers severe poisoning and leg damage before Nezuko and Kuuga save him. 150 151 153

Hashira Training

Zenitsu completes Tengen Uzui's physical training through motivation tied to Nezuko, passes the Tokito brothers' speed test by touching Yoriichi, and endures Gyomei's waterfall and strength training. 164 166 172 174

Infinity Castle

Now able to consciously wield Thunder Breathing, Zenitsu fights alongside Tanjiro, Inosuke, Giyu, and Kanao against Rui. He uses the Seventh Form, Fire God, to deliver the decisive decapitation. 179 180

Notable Quotes

“I definitely won't die! For Master, for everyone, for Nezuko!” 151

“I... I'm actually very strong!” 150