What is Kokushibo brother and what was his tragic loss story?

Nicholas Butler

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kokushibo brother

Do you know about Kokushibo brother? Kokushibo’s brother was Yorrichi Tsugikni, an impressive swordsman and the progenitor of Breathing Techniques, namely Sun Breathing, which was the core of all the forms.

What is Kokushibo brother?

Yoriichi Tsugikuni is the twin brother of Kokushibo Tsugikuni. He was a great swordsman who formulated the Shikken techniques or the breathing techniques, especially their peak: There are several techniques, and at the top of them are THE SUN techniques. However, Takahiro retained his ability with weapons and steadfast honor and remained a sympathetic figure far from his brother Michikatsu, whose jealousy led to their tragic separation. 

Early Life and Discovery of Talent

Early Life and Discovery of Talent

Yoriichi was born to the head of the Tsugikuni family during the Sengoku period and had an identical twin brother, Kokushibo. From his childhood, he was thought to be stupid and speechless by his own family, and they avoided using him in any critical tasks. However, his ability to do this was evident when he was still young and probably a child. 

Tragic Personal Loss

Kokushibo brother Yoriichi’s life was not without deep grief, though we did not see much of that aspect of him. He was in love with a woman called Uta, and they resided happily ever after, separated from everybody. But what went wrong is that one day, while getting back home, he was greeted by the dead bodies of Uta and the unborn child killed by demons. This encounter strengthened Yoriichi’s determination to defeat demons and plunged him deeper into the world of demon slayers.

Relationship with Kokushibo

Relationship with Kokushibo

The central aspect of Yoriichi’s story is the connection between the brothers, Yoriichi and Kokushibo. However, due to Yoriichi’s attempts to fortify and motivate his brother, Kokushibo’s resentment and inferiority complex only increased. This led Kokushibo to accept his inhumanity and transform into the demon Kokushibo. Yoriichi was heartbroken by his brother’s decision and turned his back, adding a deep layer of personal sadness to his life.


The tragic life of Yoruichi Tsugikuni, an exceptionally talented demon capable of blessing and cursing the Demon Slayer Corps, paved the path for its entire history and techniques. His tragic conflict with his brother, Kokushibo, raised elements of rivalry and rehabilitation, with an impact that created and embodied the necessary rage in the succeeding generations to face demons. 


Who is Yoriichi Tsugikuni?

Yoriichi Tsugikuni is a legendary swordsman in Demon Slayer: Karen Elizabeth, the Drudge of the Sword and the author of the Breathing Techniques and the Sun Breathing style of Kimetsu no Yaiba.

What are Breathing Techniques?

Breathing techniques are swordsmanship techniques that Yoriichi created for a demon slayer to boost one’s physical strength.

What personal losses did Yoriichi have?

One day, he lost his wife Yukimura and the child that was in her womb to demons, which burned the desire to kill demons even deeper within Yoriichi.

What was the tragic story between Yoriichi and his brother Kokushibo?

Yoriichi clarified this one day when he went on to support his brother Michikatsu, but he turned into a demon named Kokushibo, which caused a bitter separation between the two brothers.

How did Yoriichi die?

Yoriichi was shown to have died of old age, comfortably seated while holding on to the flute he had carved for his brother.