Kokushibo

Biodata

Feature	Value
Name	Kokushibo
Alias(es)	Tsugikuni Michikatsu; Upper Rank One
Species/Race	Demon; formerly human
Gender	Male
Affiliation	Twelve Kizuki; later acts alongside Doma against Muzan
Occupation/Role	Swordsman; former Upper Rank One
Status	Active
First Appearance	Chapter 302

Power Progression

Stage / Realm / Level	Chapter	Notes
Upper Rank One	302	Arrives at Oboro's mansion with Doma as Muzan's representative; assesses Oboro before fighting.
Soul-based concealment and Demon Sword enhancement	340	Conceals his presence from Muzan, infuses soul power into his Demon Sword, and inflicts slowly healing soul damage.
Integrated Breathing and circulation	340	His swordsmanship and breathing display an evolved integration, allowing him to pressure Muzan while resisting Muzan's cellular erosion.

Background / History

Tsugikuni Michikatsu was the elder brother of Tsugikuni Yoriichi and survived from the Sengoku period as a demon. Though much of his human memory has faded, his obsession with surpassing Yoriichi remains embedded in his soul; he still considers himself inferior to his younger brother and refuses to stop pursuing greater strength. 302 326

As Upper Rank One, Kokushibo served Muzan and participated in the search for Oboro. He and Doma visited Oboro's mansion to seek the Blue Spider Lily and Oboro's cooperation. Rather than immediately attack, Kokushibo silently observed Oboro while Doma attempted conversation. 302

Oboro overwhelmed Kokushibo after first defeating Doma. Kokushibo's Moon Breathing and swordsmanship initially neutralized much of Oboro's staff-based technique, but Oboro abandoned his weapon and used Divine Fist to incapacitate him. Kokushibo's regeneration could not keep pace with the damage. 303

Oboro later extracted Kokushibo's bloodline and skills, altered his memories, and expelled him from the city alongside Doma. 304 The experience was not fully disclosed to Muzan, leaving Muzan unaware of Oboro's true strength. 324

Over time, Kokushibo and Doma became increasingly independent of Muzan. Kokushibo openly reasoned that, since Muzan treats the Upper Ranks as tools and values strength above all else, replacing him is natural if one possesses sufficient power. 326 He later stood with Doma against Muzan's newer Twelve Kizuki and entered the Infinity Castle for Oboro's arranged confrontation. 335 338

During the Infinity Castle melee, Kokushibo ambushed Muzan and fought him to a standstill. His soul-based concealment prevented Muzan from locating him reliably, while his Demon Sword inflicted wounds upon Muzan's soul. 340

Appearance

Kokushibo presents himself as a samurai with an unsettling, inhuman face. His appearance alone is described as enough to frighten ordinary people. 302

• Six blood-red eyes that open and close across his face. 302
• Kimono patterned with purple snakes and black spots. 302
• Black riding hakama and tied-up hair. 302
• Carries an enormous flesh-and-blood Demon Sword. 303
• Later manifests a more overtly demonic appearance with three pairs of crimson eyes. 340

Personality

Kokushibo is quiet, reserved, and highly observant. He prefers to assess opponents before acting, remaining silent while Doma engages targets in conversation or provokes them. 302 324

His defining drive is an enduring inadequacy toward Yoriichi. Even after becoming a demon and losing much of his past, he remains compelled to surpass the brother whose strength is engraved upon his soul. 326

He respects strength and follows a harsh logic of power. This worldview ultimately allows him to accept rebellion against Muzan, whom he views as someone who treats demons as disposable tools. 326 Despite this independence, he disapproves of Doma's manipulative methods and remains more restrained than his companion. 337

Abilities & Skills

Moon Breathing

Kokushibo uses Moon Breathing through his Demon Sword, combining expansive blade arcs with refined swordsmanship.

• Seventh Form: Cursed Mirror Moon Reflection — launches multiple cutting slashes that cover evasion routes and the surrounding ground. 303
• Eighth Form: Moon Wheel Tail Spin — creates a circular, moon-shaped blade arc. 303
• First Form: Dark Moon — Evening Palace — produces elliptical slashes that divide into numerous moon-wheel projectiles. 340
• His swordsmanship adapts quickly to an opponent's combat patterns; he was able to read and counter Oboro's staff techniques. 303

Demon Sword

Kokushibo wields a massive, organic Demon Sword with a serrated edge and the capacity to change shape. 303 340

• The blade can sprout additional segments along its edge. 303
• When infused with soul power, its wounds damage the target's soul and do not heal quickly. 340
• Kokushibo used it to pierce Muzan's shoulder after tearing through a flesh cocoon. 340

Soul Concealment

Kokushibo developed a soul-based stealth ability that alters his presence.

• Conceals him from Muzan's perception, functioning similarly to an exceptional form of Zetsu. 340
• Allows him to attack from unexpected positions throughout the Infinity Castle. 340
• Its effectiveness is limited by endurance; a prolonged battle of attrition would endanger him once he could no longer maintain it. 340

Demon Physiology

As a powerful demon, Kokushibo possesses exceptional physical attributes and regeneration.

• His physical attributes greatly exceed Oboro's ordinary bodily strength during their first battle. 303
• He can rapidly regenerate devastating injuries, though Oboro's Divine Fist damage temporarily outpaced this recovery. 303
• His stronger body makes him less vulnerable than Doma to Muzan's cellular erosion, though he still has a limited time to suppress it. 340

Breathing and Circulation Integration

Kokushibo has incorporated breathing and circulation into his combat system rather than treating them as separate disciplines. 340

• This development strengthens the connection between his swordsmanship and his demon physiology. 340
• Oboro recognized the integration as a significant evolution of the world's power system. 340

Relationships

• Tsugikuni Yoriichi — Younger brother and lifelong standard of strength; Kokushibo's desire to surpass him persists even after his human memories fade. 302 326
• Kibutsuji Muzan — Former master. Kokushibo eventually accepts the possibility of replacing him under the demons' own doctrine of strength. 326
• Doma — Ally of convenience and fellow dissenter against Muzan. Kokushibo understands Doma's schemes but does not approve of his methods. 324 337
• Oboro — Overpowered and psychologically shaken by him; Oboro extracted Kokushibo's bloodline and skills and altered his memories. 303 304
• Gyutaro — A target in Oboro's arranged Infinity Castle conflict; Doma seeks to eliminate Gyutaro and become Oboro's sole successor. 338 341

Story Role / Major Arcs

Oboro Mansion Confrontation

Kokushibo accompanies Doma to recruit or investigate Oboro, then challenges him with Moon Breathing. His defeat establishes Oboro's overwhelming superiority and leaves Kokushibo unable to regenerate normally. 302 303

Break from Muzan

After recovering from Oboro's intervention, Kokushibo withholds the full truth of Oboro's strength from Muzan. He later joins Doma in acting independently, accepting that Muzan may be replaced by a stronger demon. 324 326

Infinity Castle Melee

Kokushibo joins Doma against Muzan and the Twelve Kizuki. Within the Infinity Castle, he uses soul concealment, Moon Breathing, and his soul-infused Demon Sword to ambush Muzan and force him into a difficult two-front battle. 336 338 340