Yaha

Biodata

Feature	Value
Name	Yaha (夜羽); addressed as “Tomioka Ye Yu” by Sabito 14.
Species/Race	Human, later undergoing Flesh Vessel reconstruction that awakens Sukuna-like physical traits 4 48 61.
Gender	Male; Giyu Tomioka’s younger brother 3.
Age	Ten when his powers awaken; twelve during his early training on Mount Sagiri 1 3 4.
Affiliation	Demon Slayer Corps; granted an alliance preserving his freedom of action 31.
Occupation/Role	Demon slayer with special authority above the Hashira and access to the Corps’ intelligence network 31.
Power Template	King of Curses—Ryomen Sukuna, bound through the Template Roleplay System 1.
Status	Alive during the battle with Muzan, but facing a 47-second vessel-collapse countdown while sustaining his domain 136.
First Appearance	The demon attack on the Tomioka household 1.

Power Progression

Yaha’s system tracks roleplay level separately from Flesh Vessel reconstruction. Template fusion reaches 100% at activation, but his subsequent abilities remain gated by roleplay milestones and his body’s capacity 1 6 48.

Stage / Realm / Level	Chapter	Notes
Sukuna template bound; fusion reaches 100%	1	Extreme negative emotions during the attack on Tsutako activate the system. Yaha immediately manifests cursed markings, enhanced strength, and Dismantle.
Roleplay level: 11%	2	Killing the household demon grants +1% and unlocks Sukuna’s Monstrous Strength (Beginner).
Roleplay level: 12%	3	Gains +1% after effortlessly defeating Sabito without a sword or Breathing Style.
Roleplay level: 18%	6	Basic Reverse Cursed Technique is identified as the next unlock at 20%; the condition requires absolute contempt for the weak in battle.
Roleplay level: 25%; beginner Reverse Cursed Technique	11 12	Destroying and humiliating the Hand Demon grants +7% and unlocks healing. Both chapters report the same milestone.
Roleplay increase; amount unspecified	17	Receives a progress notification while overpowering the poisonous Lower Rank demon.
Roleplay level: 33%	19	The Lower Rank’s annihilation awards +8%. The system reveals the 50% requirement for Domain Expansion.
Roleplay level: 48%	28	Killing Rui grants +15%, leaving two percentage points before the domain unlock.
Domain Expansion: Malevolent Shrine	32 34	The system identifies the Blue Stone Town target as a route past the 50% threshold. Yaha deploys his first complete domain, selectively destroying demon matter while sparing humans.
Progress toward Open (Flame Arrow)	35 42	Progress becomes available after Blue Stone Town. The later unlock condition demands that he burn through an opponent’s cherished martial faith.
Roleplay level: 63%; Open officially unlocked	46	Overwhelming Akaza’s martial techniques with fire completes the assessment. The output also exceeds his human body’s overload limit.
Flesh Vessel reconstruction: 12%	48	Consuming origin extracted from Akaza widens his cursed-energy channels and forms four-arm rudiments.
Flesh Vessel reconstruction: 34%	54	His reconstruction creates an expanding energy deficit and hunger for concentrated essence.
Flesh Vessel reconstruction: 36%	54	Absorbing a lesser demon’s essence adds two percentage points, but barely addresses the deficit.
Roleplay level: 65%	57	Gains +2% for disregarding formalities and imposing an overwhelming presence in the Entertainment District.
Further reconstruction; four-armed spectral manifestation	61	Gyutaro’s high-purity origin rebuilds his bones and energy channels, forcing spectral forms outward from his back.
Further essence absorption; severe mutation backlash	83 84	Gyokko’s essence overloads his vessel. Spectral arms emerge uncontrollably, and Sukuna’s instincts challenge his control.
Hantengu’s Origin consumed	92	Retrieves and swallows a finger-shaped portion after severing Muzan’s will from Hantengu. No percentage is stated.
Roleplay level: 74.5% → 75%	112	Cutting through the Infinity Castle’s spatial laws earns an increase.
Roleplay level: 75% → 76.5%	114	Knowingly advancing into Muzan’s trap to reach Shinobu loosens one restriction on Open and strengthens his fire-charged slashes.
Doma’s essence consumed; vessel threshold exceeded	124	The additional essence causes another spectral-arm eruption and uncontrolled heat release.
Roleplay increase; amount unspecified	129	Briefly uses his ruined right hand to block Kokushibo, then returns it to his pocket; the system awards another increase.

Background / History

Yaha is the younger brother of Giyu Tomioka and the younger sibling of Tsutako Tomioka. At ten years old, he is trapped beneath wreckage while a demon threatens Tsutako. His helplessness and rage trigger the Sukuna template, allowing him to free himself, dismember the attacker, and destroy its head. The power leaves his child’s body completely exhausted 1 2 6.

Over the following two years, Yaha practices secretly behind Mount Sagiri while studying under Sakonji Urokodaki alongside Giyu and Sabito. His daytime sleeping conceals nighttime experiments intended to make his lethal techniques safe around companions. He knows the Hand Demon threatens Sabito and Makomo and prepares selective wide-area cuts before Final Selection 3 4 6.

His strength eventually alarms Urokodaki, who reports that it falls outside both Breathing Styles and Blood Demon Arts. Rather than eliminate him, Kagaya Ubuyashiki offers an alliance, unrestricted intelligence access, and freedom of action. Yaha accepts and immediately requests the Upper Ranks’ locations 15 31.

Appearance

Yaha normally has black hair, black eyes, and a pale complexion; activating Sukuna’s power gives him scarlet eyes and spreading black cursed markings 1 11 37.

• Cursed markings: Rise from beneath his collar, crossing his neck, jaw, cheeks, and the corners of his eyes; they recede when his power subsides 16 37.
• Usual clothing: A black Corps uniform, military-style boots, and a dark haori. Tsutako’s later haori has a subtle wisteria pattern at the collar 20 35 37.
• Resting expression: Frequently half-lidded or “dead-fish” eyes, accompanied by an apparently bored posture and hands tucked into his pockets 75 129.
• Reconstructed traits: Dark red streaks appear beneath his shoulder blades, followed by translucent arms and four-armed spectral forms 48 61 83 84.
• Late-battle injuries: His right hand develops extensive burns, exposed tissue, dislocated fingers, and damaged energy channels; the left hand later begins suffering similar damage 125 136.

Personality

Yaha presents himself as lazy, abrasive, and contemptuous. He sleeps frequently, complains about training, and humiliates opponents by treating their strongest attacks as insignificant. His refusal to draw a sword is often deliberate: he considers many enemies unworthy of the effort 3 5 17.

His attachment to others conflicts with the system’s demand that he despise weakness. Rather than abandon the people he wants to protect, he defines predatory demons as the “weak” deserving his contempt. He also rescues a surviving child despite Sukuna’s instincts urging him to dismiss fragile human life 6 7 20.

Yaha dislikes gratitude, formalities, and interference, but repeatedly protects people while denying concern for them. He accepts Tsutako’s haori despite insulting it, conceals injuries from Shinobu, and knowingly enters a trap to reach her. His brutality toward demons contrasts with his determination not to let Sukuna’s hunger consume someone he values 35 61 84 114 125.

Abilities & Skills

Dismantle

An invisible cutting technique delivered through small finger gestures or through a blade 1 18 128.

• Produces silent, mirror-smooth cuts through stone, metal, buildings, and demon bodies 4 14 17.
• Can shave away a thin layer of flesh rather than sever an entire limb, demonstrating fine control 18.
• Inflicts wounds that resist demon regeneration, including Akaza’s permanently missing half-ear 17 43 44.
• Is not unavoidable: Kokushibo redirects some moon blades around its coverage through precise trajectory correction 128.

Cleave

A wide-area grid of invisible slashes, developed to sever multiple threats without injuring nearby allies 6.

• Early tests establish a 15-meter range and pieces as small as three centimeters 6.
• Initially cuts indiscriminately; repeated practice lets Yaha leave a selected tree entirely unharmed 6.
• Destroys Rui’s blood-thread attacks and advances through their defenses 27 28.

Domain Expansion: Malevolent Shrine

An unenclosed domain manifested as a shrine of bone, allowing Yaha to impose precise cutting rules throughout its affected space 32 34.

• At Blue Stone Town, targets inanimate matter and demon flesh while completely avoiding human bodies 34.
• Prevents Gyutaro and Daki from regenerating after they are cut apart 61.
• Strikes Muzan hundreds of times within a single second 136.
• Sustaining a complete domain heavily strains his vessel; its later use carbonizes his left-hand blood vessels and triggers a collapse countdown 34 136.

Open / Flame Arrow

A destructive fire ability officially unlocked after Yaha crushes Akaza’s faith in his martial arts 42 46.

• Manifests as dark red flame and leaves Akaza’s erased limbs unable to regenerate 44 46.
• Can be channeled through the New Blade at full power, erasing the Sewing Abomination without ash or residue 116.
• Burns through the Infinity Castle’s spatial self-repair mechanisms 114 116.
• Its output can exceed his vessel’s capacity, rupturing vessels and accumulating damage faster than healing can repair it 46 125.

Cursed Technique Eight

A later technique that projects densely layered grid slashes or concentrates their cutting laws onto his sword 114 123.

• Wide-area deployment consumes 3% of his current vessel capacity per use 114.
• Blade coating compresses the technique onto a three-millimeter cutting surface, increasing density fortyfold and extending a single cutting line 500 meters 114.
• Lingering cutting laws prevent severed castle structures from repairing themselves 114.
• A zero-windup strike defeats Kokushibo’s predictive reading and causes regeneration-resistant carbonization around his neck 129.

Reverse Cursed Technique

A healing ability unlocked at beginner level after the Hand Demon’s defeat 11 12.

• Restores Rengoku’s fatal injuries and rapidly repairs Yaha’s broken ribs after Akaza’s kick 43 44.
• Repairs damage caused by reconstruction and excessive technique output 46 51.
• Has a finite repair rate: accumulated energy-channel damage in his right hand repeatedly outpaces it 111 125.
• Cannot maintain normal output once the vessel’s channels rupture extensively 111.

Origin Extraction and Flesh Reconstruction

Yaha extracts concentrated demonic origin, compresses it into cursed objects, and consumes it to rebuild his body 47 48 61.

• Upper Rank origin widens energy channels, reconstructs bones, and nourishes emerging Sukuna-like arms 48 61.
• Lesser demon essence provides much smaller reconstruction gains 54.
• He can halt Hantengu’s self-destruction and sever Muzan’s controlling will before recovering the Origin 92.
• Excessive absorption causes severe hunger, unstable mutations, and struggles against Sukuna’s predatory instincts 54 83 84 124.

Physical Power and Combat Precision

Yaha’s strength and reactions allow him to overpower trained swordsmen and demons without relying on a Breathing Style 3 17 43.

• Catches Sabito’s strongest wooden-sword strike between two fingers 3.
• Stops Akaza’s Annihilation Type barehanded and throws him through three trees 43.
• Dodges rapid barrages with minimal movements, often keeping both hands in his pockets 14 44 78.
• Resists the poisonous wind blades and mist used by the Lower Rank demon 17.
• Uses high-speed aerial travel to carry Shinobu between locations 55 73.

Perception and Instruction

Sukuna-derived perception lets Yaha inspect supernatural structures and detect distant presences 22 31 37.

• Identifies Nezuko’s freedom from Muzan’s blood-control network 22.
• Sees Kagaya’s curse embedded in his marrow and soul rather than mistaking it for ordinary organ failure 31.
• Detects Akaza approximately thirty kilometers ahead and locates Hantengu’s hidden body underground 37 91.
• Presents no fighting spirit for Akaza’s Compass Needle to read during their confrontation 43.
• Diagnoses flaws in breathing, stance, and sword transitions; corrects Giyu, Tanjiro, Zenitsu, and Inosuke despite never practicing a Breathing Style himself 3 4 53.

Equipment / Weapons / Items

• Black Nichirin Blade — His original jet-black sword, usually left sheathed because his fingertip techniques suffice 17 37.
• New Blade — A pitch-black weapon bearing cursed markings and two dark red grooves. It withstands Open at full power without chipping or cracking 100 106 116.
• Tsutako’s amulet — A handmade protective charm kept over his heart; a reminder of why he seeks greater power 6.
• Tsutako’s haori — Accepted despite his insults; its collar bears a subtle wisteria pattern 35 37.
• Black-and-gold Command Token — Used to establish his authority when entering the Swordsmith Village 75.
• Origin-derived cursed objects — Finger-shaped concentrations of demonic origin consumed for reconstruction rather than retained as weapons 48 61 92.

Relationships

• Giyu Tomioka — Older brother and a central reason for Yaha’s protective choices. Yaha criticizes his weaknesses but recognizes the exceptional steadiness of his breathing foundation 3 4 31.
• Tsutako Tomioka — Older sister whose near-death triggers his awakening. Her letters, amulet, and haori remain important personal gifts 1 6 35.
• Sakonji Urokodaki — Master who supervises his training and reports his dangerous, unexplained power to Kagaya 5 15.
• Sabito — Fellow student and friend. Their one-sided spars unsettle Sabito, but Yaha answers his question about his identity with “Your buddy” 3 14 15.
• Makomo — Fellow student whom Yaha prepares to protect from the Hand Demon 6 11.
• Kagaya Ubuyashiki — Alliance partner who exchanges intelligence and autonomy for Yaha’s cooperation, trusting his personal attachments to keep him on humanity’s side 31 55.
• Shinobu Kocho — Initially investigates him as a possible threat; later becomes his monitor, traveling companion, caregiver, and someone he fiercely protects. Her claim that he is her husband is a cover story used to stop a confrontation with a patrol 23 55 73 84 118 125.
• Kyojuro Rengoku — Respects Yaha after Blue Stone Town. Yaha intervenes on the Mugen Train route and heals his fatal wounds 35 43.
• Tanjiro Kamado — Saved and later instructed by Yaha, who sharply rejects his sympathy for demons 21 22 53.
• Nezuko Kamado — Initially treated as a threat, then spared after Yaha recognizes her independence from Muzan’s control 21 22.
• Muichiro Tokito — A talented Hashira whom Yaha calls a “glass doll.” Muichiro later approaches him while severely injured and refuses to leave until Yaha responds 83 95 96.
• Sanemi Shinazugawa — Hostile toward Yaha’s privileges; repeatedly provoked by Yaha’s taunts 31 51.
• Akaza — Defeated, mutilated, and deliberately left alive to carry Yaha’s challenge to Muzan 46 47.
• Muzan Kibutsuji — Principal enemy and source of the origin Yaha consumes. Muzan fears his attacks, investigates his limits, and targets Shinobu as his personal weakness 53 61 70 134.
• Ryomen Sukuna’s instincts — The template supplies Yaha’s power but also introduces hunger, contempt, and urges that threaten his autonomy 20 54 84.

Story Role / Major Arcs

Arc	Yaha’s involvement
Tomioka household attack	Awakens the Sukuna template to save Tsutako and kills the attacking demon 1 2.
Mount Sagiri and Final Selection	Refines selective cutting, defeats the Hand Demon, unlocks healing, and helps bring the students back alive 6 11 13.
Lower Rank hunts and Mount Natagumo	Annihilates a poisonous Lower Rank, rescues a child, saves Tanjiro, studies Nezuko’s unusual blood, and kills Rui 19 20 21 22 28.
Corps alliance and Blue Stone Town	Secures freedom and intelligence access, then uses Malevolent Shrine to destroy the demon threat without cutting the human shields 31 34.
Mugen Train	Intervenes against Akaza, saves Rengoku, unlocks Open, and begins origin-driven vessel reconstruction 35 43 46 48.
Entertainment District	Receives expanded operational privileges, defeats Gyutaro and Daki, consumes Gyutaro’s origin, and attempts to restart Tengen’s failing heart 55 61.
Swordsmith Village	Challenges Yoriichi Type Zero, suffers backlash from Gyokko’s essence, defeats Hantengu, and examines Yoriichi’s restored sword as potential material rather than a sacred relic 78 83 92 98.
Infinity Castle	Cuts his own route through the castle, rescues Shinobu from Doma, consumes Doma’s essence, and fights Kokushibo while managing severe injuries 112 114 118 124 129.
Battle with Muzan	Leads the surviving slayers to Muzan and deploys Malevolent Shrine despite his failing vessel. The documented battle ends with his collapse countdown at 47 seconds 134 135 136.

Notable Quotes

“I've never even practiced a Breathing Style. Where would I get a technique?” 3

“I'm strong.” 3

“Your buddy.” 15

“Tell him to wash his neck and wait for me in the Infinity Castle.” 47

“There are two things I hate most.”
“First, trash that interrupts my sleep.”
“Anyone who touches one of mine.” 91