What happened to Koyuki in Demon Slayer? Explained

One of the most iconic characters from Demon Slayer was the Upper Moon Four demon, Akaza. While he was always keen to fight strong opponents and showed aggression, his past was different. Akaza's hunger for strength stemmed from his trying to protect his sick father and his fiancée, Koyuki.

While this was revealed in the series, many fans asked the question, "What happened to Koyuki?", given her significance in the role of Akaza becoming a demon. Koyuki and her father, Keizo, died from poisoning after drinking the water from a well that was poisoned by a rival dojo.

Disclaimer: This article contains spoilers from the Demon Slayer anime/manga.

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Koyuki's life with Hakuji and her end, explained

Koyuki's death in the Demon Slayer manga (Image via Shueisha)

In chapter 154 of the Demon Slayer manga, titled A Strong Wave of Nostalgia, Akaza was finally beheaded by Tanjiro and Giyu. However, even after being beheaded, Akaza's body was still standing and willing to fight. As he was approaching Giyu, an apparition appeared and held his arms, asking him to stop. The apparition that tried to stop Akaza was Koyuki.

This sequence led to a flashback of Akaza's life before he was a demon and was known as Hakuji. Due to his father's sickness, Hakuji became a pickpocket when he was very young to gather money for medicine. However, he was caught several times, and when the news reached his father, Hakuji's father hanged himself.

After his father's demise, Hakuji became very aggressive. When he was banished as a pickpocketing criminal from Edo, he began beating everyone he crossed paths with. During one such altercation, Hakuji met Keido and was knocked out by him, only waking up an hour later. He was then taken by Keido to the dojo, where Hakuji could train himself, and where he first met Koyuki, Keido's daughter.

Hakuji's life took a turn when he joined the Dojo, as he trained and found a place to live. He learned over time that the Kenjutsu Dojo next to their Keido's Soryuu Dojo was jealous of them and always wanted to acquire their land. Keido later offered Hakuji to handle the Soryuu Dojo and marry Koyuki, which Hakuji accepted.

One day, when Hakuji went to visit his dad's grave and talk to him about the marriage, the Kenjutsu Dojo pupils poisoned their water well. As Hakuji was returning, he saw some people crowding in front of the Dojo. Upon getting closer, he heard that both Keido and Koyuki had died after drinking the poisoned water from the well.

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How Koyuki's death partially shaped Demon Slayer's story?

Muzan approaches Hakuji to turn him into a demon (Image via Shueisha)

As Hakuji found out about Koyuki's death, he went on a rampage, killing everyone he could set his sights on. In chapter 155 of the Demon Slayer manga, titled The Useless Komainu, one night after killing several people, Hakuji was approached by Muzan, who was intrigued upon hearing the stories of Hakuji's rampage.

Hakuji, still blinded by his rage, attacked Muzan and was smashed on the head immediately. Muzan then exclaimed that he would give Hakuji some of his blood and turn him into a demon, as he was looking to create twelve strong demons, who were later known as the Twelve Kizuki. This is how Muzan created Akaza, who became one of the most ruthless members of the Twelve Kizuki.

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Final thoughts

While this article answered the question of what happened to Koyuki, it can be noted as ironic as Koyuki's death is what caused Hakuji to become the demon Akaza. She is also the reason why Akaza stopped fighting and passed on in the Infinity Castle arc.

While Akaza can be considered one of the most vicious and strongest demons in the Demon Slayer series, he was not always like that and was forced to take the part after surrendering to his rage. The story of Akaza and Koyuki is very emotional and has also impacted the narrative greatly by adding his character as one of the toughest opponents the demon slayers are about to face, as the anime continues.

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