Zenitsu Agatsuma

Biodata

Power Progression

Background / History

Training under Jigoro

Zenitsu trains under Jigoro Kuwajima alongside his senior fellow disciple, Kaigaku. Despite working hard, his inability to learn anything beyond Thunder Breathing’s First Form leaves him convinced that joining the Corps will get him killed. Kaigaku, who knows every established form except the First, treats him with contempt and jealousy 49 50.

Ye Chen first encounters him hiding in a tree and refusing to continue training. Lightning strikes Zenitsu, turning his black hair yellow but causing only minor burns and injuries from his fall. After testing his swordsmanship, Ye Chen discovers that a Light Ball can strengthen him and gives him the item in exchange for practicing Pikachu’s cry 49 50 51 52.

Joining the Corps

Zenitsu joins the same Corps intake as Tanjiro and Inosuke and accompanies them to Ye Chen’s base after Final Selection. Hoping to accompany a Hashira on missions, he invokes Ye Chen’s promise of help by calling out “Pikachu.” Ye Chen instead tests him against Inosuke; Zenitsu loses after becoming distracted by the unfamiliar commands shouted from behind him 62 63 64.

Although terrified by reports of an entire town’s disappearance, Zenitsu refuses the opportunity to stay behind because he cannot let the responsible demons escape punishment. During the investigation, he fights while asleep and protects his companions as they recover from a sleep-inducing ambush 64 65 66.

Afterward, he supports Tanjiro’s defense of Nezuko. Initially mistaking their closeness for romance, he changes his attitude immediately upon learning they are siblings and begins treating Tanjiro as a prospective brother-in-law. Ye Chen later uses this infatuation to secure his cooperation in a rematch against Inosuke, which Zenitsu wins 76 77 78.

Jigoro’s threatened seppuku

Ye Chen takes Zenitsu to visit Jigoro after learning of Kaigaku’s disappearance. When told that Kaigaku has become a demon and Jigoro intends to take responsibility through seppuku, Zenitsu clings to his teacher and begs him not to die. Their private conversation leaves Zenitsu believing that Jigoro will abandon the plan; he thanks Ye Chen and resolves to make Kaigaku answer for what he has done 82 83.

Spider Mountain and the final conflict

On Spider Mountain, Zenitsu kills the older spider brother and later frees Nezuko by severing Urogi’s claw. He cannot overpower Urogi while escorting her and needs Nezuko’s counterattack to halt the pursuit 84 89.

During the battle against Zohakuten, Tanjiro sends him to locate Hantengu’s true body. Following information supplied by Ye Chen, Zenitsu attacks the enlarged Cowardice Demon’s heart, where the tiny true body is concealed. He awakens his mark, beheads Hantengu, and collapses; Zohakuten begins crumbling as a result 90.

Zenitsu eventually confronts Kaigaku alone. He initially considers requesting Tamayo’s human-restoring medicine if Kaigaku was forcibly transformed and has committed no heinous acts. Kaigaku’s gleeful dismissal of Jigoro’s suffering ends that possibility, and Zenitsu kills him with his self-created Seventh Form 101.

After Muzan’s death and the Corps’ disbandment, Zenitsu continues pursuing Nezuko. Whether she reciprocates remains unresolved 107.

Appearance

• Yellow hair — originally black; changes color after a direct lightning strike during training 49.
• Lightning-like arm mark — manifests when he awakens his Demon Slayer Mark against Hantengu 90.

Personality

Zenitsu is fearful, loudly pessimistic, and prone to crying or exaggerating his injuries. He repeatedly seeks protection from stronger fighters and uses his “Pikachu” impression to solicit Ye Chen’s help. His complaints conceal genuine effort: Jigoro recognizes that he works hard despite his discouragement 49 50 62 64.

His fear does not erase his pride or conscience. Inosuke’s insults provoke him into fighting seriously, and the empty-town atrocity motivates him to undertake a mission he could have refused. His attachment to Jigoro produces a firmer resolve against Kaigaku, while their eventual confrontation shows him deliberately controlling his anger 63 64 83 101.

He is also an persistent flirt. His attraction to Nezuko leads to jealousy, gifts of flowers, and repeated arguments with her protective brother. Calling her his wife reflects Zenitsu’s aspirations, not an established relationship 76 84 107.

Abilities & Skills

Thunder Breathing

Zenitsu specializes in explosive movement and rapid sword strikes rather than a broad repertoire of established forms 49 50.

• First Form: Thunderclap and Flash — a high-speed charge and slash; used to kill the older spider brother 50 84.
• Sixfold Strike — chains rapid attacks across multiple targets; kills six demons in under two seconds and later overwhelms Inosuke’s defense 66 77.
• Eightfold Strike — an expanded sequence used against Kaigaku with his mark and Light Ball active 101.
• Seventh Form: Fire Thunder God — his own technique; cuts through Kaigaku’s dense lightning barrage before delivering a fatal decapitation 101.
• Limits — overuse leaves him aching after the town battle; even his First Form struggles against Kaigaku’s surrounding slashes 76 101.

Combat while asleep

Zenitsu can fight effectively while unconscious, displaying composure and power sharply at odds with his usual panic 49 66.

• Decapitates demons and protects recovering teammates during the sleep-inducing ambush 66.
• Speaks while asleep, including announcing techniques and expressing trust in Tanjiro 66 76.
• Is not restricted to sleeping combat: he defeats Inosuke and confronts Kaigaku while awake 77 78 101.

Demon Slayer Mark

His lightning-like mark awakens during the decisive strike against Hantengu 90.

• Later activates it together with the Light Ball against Kaigaku 101.
• Has its associated curse removed by Ye Chen 106.

Equipment / Weapons / Items

• Light Ball — yellow bead supplied by Ye Chen that amplifies Zenitsu’s Breathing Style. Jigoro cannot activate it; its unexpected compatibility with Zenitsu inspires the “Pikachu” nickname 51 52.
• Nichirin Blade — used to decapitate demons, including Hantengu and Kaigaku 66 90 101.
• Wooden practice sword — used in Ye Chen’s tests and both matches against Inosuke; with enhancement, it can fell a small tree and break Inosuke’s wooden swords 50 51 63 77.

Relationships

• Jigoro Kuwajima — master, affectionately called “Grandpa” or “Gramps.” Zenitsu’s intervention helps dissuade him from committing seppuku 49 82 83.
• Ye Chen — senior, benefactor, and frequent tormentor. Gives him the Light Ball, coaches his rematch, and helps save Jigoro; Zenitsu privately complains about his eccentric behavior 51 77 80 83.
• Kaigaku — former senior fellow disciple turned enemy. His contempt and betrayal culminate in Zenitsu killing him 50 83 101.
• Tanjiro Kamado — fellow Corps member and teammate. Zenitsu trusts his kindness but repeatedly antagonizes him by pursuing Nezuko 62 76 84.
• Nezuko Kamado — romantic interest and protected companion. Zenitsu rescues her from Urogi; his pursuit remains unresolved at the story’s end 76 89 107.
• Inosuke — teammate and sparring rival. Wins their first match after Zenitsu is distracted, then loses the rematch 63 64 77 78.

Notable Quotes

“Those demons did something so horrible. I can't let them get away with it either.” 64

“And I won't forgive Kaigaku, either. I'll make him pay.” 83