Summary
- Kokushibo and Yoriichi share a deep connection through brotherhood and the development of breathing styles.
- Yoriichi trained demon slayers but failed, leading to the creation of the unique breathing techniques.
- Kokushibo’s jealousy of his brother led him to become a demon and, despite his power, he could not defeat Yoriichi.
The 12 Moons are the elite-level demons that battle on behalf of Muzan Kibutsuji and the most powerful antagonist of Demon Slayer. At the top of the ranks is the extremely powerful and skilled Kokushibo, a demon with a distinct appearance wielding a katana. Fans may have noticed a distinct resemblance between Kokushibo and the legendary demon slayer Yoriichi. On top of that, the mere fact that a demon wields a katana may seem strange to fans.
In fact, Kokushibo and Yoriichi are more closely connected than most audiences imagine. Here’s what you need to know about the deep personal connection between Upper rank One and the legendary Demon Slayer.
Related
Demon Slayer: Why Does Tanjiro Know Two Breathing Styles?
In Demon Slayer, unlike others, Tanjiro uses Two Breathing Styles. What makes him so special?
Yoriichi and Kokushibo, The First Two Demon Slayers
The Tragic Twins
Kokushibo was born as Michikatsu Tsugikuni, and he had a younger twin brother named Yoriichi Tsugikuni. During that time, male twins were considered to be a bad omen. Therefore, their father considered killing Yoriichi. Their mother stood heavily against this and convinced her husband to, instead of killing the baby, send him away to become a monk when he turned 10. Yoriichi was often kept in a separate tiny room away from the rest of the house, and he spent much time clinging to his mother’s side. He was also believed to be deaf and mute. Meanwhile, Michikatsu trained in swordsmanship with his tutor with the goal of one day becoming a Samurai.
At night, Michikatsu would often sneak out to visit his younger brother. One day, he gifted him a flute that he had crafted himself. Yoriichi would often watch his older brother train for hours on end, until one day Michikatsu’s tutor asked the younger brother to try his hand at sword practice. Yoriichi took a deep breath and swiftly landed four blows on the tutor, shocking his older brother. Michikatsu, impressed by his brother, asked him about his secret and how he was able to do that, to which his brother replied that when he breathed he was able to see the muscles and the energy flow in the tutor, hinting at a special ability that would eventually become Sun Breathing.
Related
Demon Slayer: Did Tanjiro Surpass Yoriichi?
Tanjiro came a long way in Demon Slayer and became a powerful warrior. But was he ever able to surpass Yorichi?
Years later, the twins’ mother passed away due to a terminal illness, and Yoriichi said goodbye to his older brother and left the house on his own, to which Michikatsu simply watched him leave in silence, keeping his jealousy over his extremely skilled and talented brother repressed. Michikatsu would eventually become a powerful samurai and marry and have two children. One day, his camp was attacked by a demon and all of his subordinates were killed, leaving him the sole survivor. Surprisingly, Yoriichi arrived at the scene saving his older brother from the demon. Michikatsu saw that his twin had become an extremely powerful swordsman far beyond his ability and that he had become a demon slayer. He left his family to train with his brother and the rest of the demon slayers.
I will stop your bleeding. Humans are so fragile. However… if you bleed to death… or if his lordship doesn’t approve of you… and you die… then death was always your fate. In that case… you were no greater a man than that. Don’t you… agree?
He saw how his brother attempted to teach Sun Breathing to the other demon slayers without success, so he altered breathing styles to suit each of their strengths, creating the breathing techniques. Eventually, he awakened a slayer mark and developed his unique breathing style derived from his brother’s Sun Breathing called Moon Breathing. Michikatsu was increasingly frustrated because he was unable to surpass his younger brother in skill and power, and he eventually met Muzan Kibutsuji, who persuaded him to become a demon.
Because he was a demon slayer, Michikatsu took three whole days to properly transform into a demon and, when he did, he adopted the name Kokushibo. As Upper rank One of the 12 Demon Moons, Kokushibo was by far Muzan’s most powerful subordinate, and he slaughtered countless demon slayers on behalf of Muzan. One day, Yoriichi confronted Muzan and brought him to his limits and almost killed him in the process, but the demon lord was able to escape.
Related
Demon Slayer: The Sunrise Countdown Arc, Explained
The Sunrise Countdown Arc marks the final stand against Muzan, bringing Demon Slayer to its intense and emotional climax.
60 years later Kokushibo met his brother once again, and he was disgusted after seeing him grow old and decrepit. However, before he could even react, Yoriichi attacked him swiftly and slit his throat, but while being consumed by his rage and jealousy of his brother, Kokushibo noticed that the old Yoriichi had cried after seeing what his older twin had become and died of old age while he stood. Kokushibo was angered and disappointed that he wasn’t able to defeat his brother or even have a proper duel with him, that even after becoming an extremely powerful demon and his brother growing old, he was still far behind his younger twin. In a fit of rage, he slashed his corpse in two, accidentally slashing the flute that he had gifted him when they were children. Upon seeing the flute and realizing that all these years his brother had cherished him, he shed a tear and decided to keep the flute.