Yoriichi Tsugikuni vs Kokushibo was a brief but pivotal skirmish that took place in a field outside a pagoda, roughly 400 years before the Demon Slayer Corps' last campaign against Muzan Kibutsuji. It focuses on the clash between twin brothers Yoriichi and Michikatsu Tsugikuni, the former being a long-banished Demon Slayer and the latter a transformed Demon Slayer taking up the title as Upper Rank One by the name Kokushibo.
Prologue[]
Even as children, Michikatsu held intense envy towards Yoriichi.
Ever since they were children, Michikatsu had envied the innate strength and skill Yoriichi held when wielding a blade. After Yoriichi left their home, his envy turned to hatred when he read his mother's diary following her death, which revealed that Yoriichi had known everything about their mother's illness and supported her in her last moments, despite initially believing he was a weak child who clung to her at all times. Even after becoming a samurai and a respected swordsman in his own right, when reunited with his brother in a fateful encounter, Michikatsu still coveted Yoriichi's skill and became a Demon Slayer as a pursuit of greater strength, hoping to surpass him.
In time, both brothers became tremendous Demon Slayers in their own right; Yoriichi had developed his style into what would later become known as Sun Breathing, while Michikatsu, in his inability to use the style, developed his own style, Moon Breathing. However, as a man obsessed with glory and legacy, Michikatsu became frustrated when in response to him voicing concern that their techniques would die out without worthy successors, Yoriichi expressed optimistic indifference. His disillusionment was furthered when he noted that those who awakened their Demon Slayer Marks died at 25 years old, with no exceptions. Due to his desire to further his legacy and finally surpass his brother, when Muzan offered Michikatsu the chance to demon a demon, he accepted. Michikatsu, now Kokushibo, lost contact with his brother, and in time rose to become Upper Rank One of the Twelve Kizuki. Unbeknownst to him, Yoriichi was banished from the Demon Slayer Corps, with Michikatsu's betrayal being a major contributing factor.
Kokushibo stunned to see Yoriichi remains the same powerful warrior as his prime.
60 years after his transformation, as Kokushibo walked through a wheat field near a pagoda, he saw the one thing he would never believe happened: his younger twin brother, alive and elderly. This greatly confuses Kokushibo, as the last time they saw each other was when they were both still Demon Slayers 60 years ago, making Yoriichi an 80-year-old man. Kokushibo cannot fathom how Yoriichi has lived past the age of 25, despite having the Demon Slayer Mark.
With a hoarse voice, Yoriichi pities his older brother; realizing the person he adored the most has become a demon, having murdered and consumed many innocent people, tears began running down his face. Kokushibo became bewildered beyond relief to see the person he has never seen show any emotion in his life crying in the flesh. Due to his demonic morals from Muzan however, he knows that if any Demon Slayer should point their weapon at him, he has to attack.
Within the next moment, all of his "strange" feelings are blown away instantly when Yoriichi takes his stance to face the Upper Rank. The weight of the air itself due to the pressure of Yoriichi taking his stance is comparable to Kokushibo as having two enormous boulders resting on his shoulders. Because of this, even Kokushibo agreed that Yoriichi's stance was absolutely impeccable, having no single opening or flaw whatsoever.
Battle[]
Kokushibo's neck sliced by Yoriichi.
Yoriichi warns Kokushibo to prepare before he lunges forward and slices Kokushibo's neck, without the chance for him to even unsheathe his blade. This angers the Upper Rank even further, leading him to question why he was always the "special one" and that, despite being a very elderly man, he still retained his level of power from his prime. Filled with hatred and envy, Kokushibo readies his sword with an overpowering drive to kill Yoriichi, despite in his heart knowing that the very next attack will behead him. However, that attack never comes. Kokushibo sees Yoriichi standing on his feet, slumped down, not moving a single inch and with his blade in the ground, causing him to realize that Yoriichi had died.
Aftermath[]
Kokushibo brimmed with envy and self-worthlessness from Yoriichi's innate talent.
Despite emerging victorious, Kokushibo's anger boils over upon seeing that his continually excelling brother had appeared before him after transcending everything and dying of old age instead of losing a battle, as well knowing that even Muzan couldn't lay a scratch on Yoriichi. As such, his sole chance at a fair battle was now gone and his brother remained an undefeated champion now and forever.
Enraged by the feeling of inferiority, he spitefully slashed Yoriichi's body in half, but inadvertently broke the flute he gifted his brother as a child. Seeing that Yoriichi still thought highly of him even after his transformation, Kokushibo couldn't help but shed a tear. Unable to truly sever his bond with his brother, he decided to keep the flute, a trinket he would keep until death.
Trivia[]
- Since by this point, Yoriichi was long excommunicated from the Demon Slayer Corps, this is the only battle in the series where a Demon Slayer was unaffiliated.
References[]