Who Is The Upper Moon Rank One Demon In Demon Slayer?

During Demon Slayer Season 3’s debut episode, the leading member of the Twelve Kizuki (Upper and Lower Moons) was introduced, piquing fans’ interest. Here is what we know about Kokushibo, the Upper Moon Rank One Demon.

Note: This article contains some Demon Slayer Manga Series spoilers, so proceed cautiously!

Who is Kokushibo, The Upper Moon Rank One?

Kokushibo, who holds the highest rank among the Twelve Kizuki (the twelve strongest demons in Demon Slayer), was once a human named Michikatsu Tsugikuni. Having lived for almost half a millennium, he has become an incredibly powerful demon, with only the main antagonist, Kibutsuji Muzan, surpassing his strength. A key reason for Kokushibo’s formidable power is the large quantity of Muzan’s blood that flows within him, which has greatly enhanced his abilities and status as a demon.

NameKokushibo (Michikatsu Tsugikuni)
AgeOver 500 years old (physically in his 30s)
AffiliationTwelve Demon Moons (Upper Moon One)
StatusAlive (Anime)
WeaponBlood Demon Art, Six-bladed sword
AbilitiesMoon Breathing, Enhanced senses, Regeneration
Marraige StatusUnknown


In the anime, Kokushibo appears as a tall man with the unique feature of having six eyes. Each of his eyes has special markings, similar to the other Kizuki members. The symbols in Kokushibo’s eyes mean “Upper Moon” and “One,” highlighting his role as a highly-skilled fighter and Muzan’s deadliest ally. He is typically shown wearing a traditional kimono, and his hair is arranged in a spiky fashion. Interestingly, before becoming a demon, Kokushibo was a demon slayer. His twin brother, Yoriichi Tsugikuni, who holds the title of the strongest demon slayer in history, was his mentor and trainer.


At first glance, Kokushibo might seem like a prideful monster who constantly shows off his strength. In reality, though, he is calm and composed, exuding a mysterious presence that often intimidates his enemies. In the opening episode of Season 3, viewers witness a heated confrontation between Kokushibo and Akaza, which highlights Kokushibo’s fierce nature. He is unwaveringly loyal to Muzan, as all his actions serve Muzan’s interests.

Who is Kokushibo, The Upper Moon Rank One?

During his time as a human, Kokushibo was envious of his younger brother’s superior talents. Despite this jealousy, he genuinely loved and admired his sibling, recognizing the positive qualities and accomplishments of his brother.

How Kokushibo Became A Demon?

Kokushibo’s transformation into a demon is a captivating aspect of his story. As a human, Kokushibo experienced feelings of envy and frustration due to his younger brother’s extraordinary talents as a demon slayer. This internal struggle eventually led him to make a fateful decision.

Seeking power to surpass his brother, Kokushibo abandoned his humanity and embraced the dark path of becoming a demon. He accepted the blood of Kibutsuji Muzan, the series’ primary antagonist, which triggered his metamorphosis into a fearsome demon. The process not only granted him immense strength and abilities but also significantly extended his lifespan, allowing him to live for nearly 500 years.

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As a demon, Kokushibo rose through the ranks to become the top member of the Twelve Kizuki, proving his might and earning the respect of demons and the fear of demon slayers alike. Despite his new existence, the memories of his past life and his complex relationship with his brother continued to influence him, shaping his character and actions throughout the series.

Abilities of Kokushibo

Kokushibo’s powers are a major source of fascination for fans! His formidable aura alone was enough to break Muichiro, the Mist Hashira’s, spirit to fight during a battle. One of Kokushibo’s techniques, body absorption, enables him to consume the bodies of vanquished foes. He can even employ the Demon Slayer Powers he gained through his Demon Slayer Mark. Kokushibo practices the Total Concentration Breathing Style, a highly effective Breathing Technique.

In addition to these skills, Kokushibo possesses Highly Sensitive Perception, Regeneration, Durability, and Extreme Speed & Reflexes, making his body as resilient as stone and impervious to harm. His Flesh and Sword Manipulation ability allows him to change the structure of both his body and sword, as the weapon itself is made of his flesh.

With his Transparent World ability, Kokushibo can see through an opponent’s body and evaluate their strength. In the series’ final arc, he scrutinizes Gyomei, the Stone Hashira. His Unbreakable Will originates from his past with his more skilled brother. Kokushibo’s strategic intelligence helps him assess his environment and his adversaries’ Breathing Techniques, as demonstrated during his fight with Muichiro.

Who is Kokushibo, The Upper Moon Rank One?

When Kokushibo’s head was cut off in a battle against the Stone Hashira, he activated his Monster Transformation ability, turning into a monstrous being covered in protruding fangs. During this transformation, he asserted that any attack on him would be useless, as he could now counter everything, and only exposure to sunlight could kill him.

What do you think of Kokushibo? Can Tanjiro and his friends manage to defeat him in the future without any casualties? Share your opinions in the comments section below!

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