Follow us along as we unravel the complex past lives of the legendary Upper Moon Demons’ pre-demonic existence. But beware, as you might need more than just tissues to get through some of the heart-wrenching backstories (sorry, Doma, you don’t qualify).
Please be aware that this article contains significant spoilers for those who have not yet delved into their stories. Additionally, this article delves into sensitive topics and situations, including instances of abuse, death, violence, and other forms of trauma. Reader discretion is strongly advised.
Upper Moon 1: Kokushibo
Chapter 177 unveils Kokushibo’s history; where he had a twin brother named Yoriichi, who was deemed inauspicious since they would cause power struggles. Yoriichi had a disfiguring birthmark, and as a result, their father commanded his execution. However, their mother was consumed by intense fury and indignation upon hearing this and instead arranged for Yoriichi to become a temple priest when he reached the age of ten.
Despite being siblings, Kokushibo and Yoriichi had different lives in terms of their rooms, clothing, education, and even meals, causing Yoriichi to remain by their mother’s side. Because of this, Kokushibo perceived Yoriichi as childish and pitiful.
To avoid their father’s wrath, Kokushibo visited Yoriichi’s cramped three-tatami room secretly and gifted him a flute once. Kokushibo recounted that Yoriichi had never smiled since he was a baby, and he only began speaking at the age of seven. Yoriichi’s first words were, “Brother is your dream to become the strongest samurai in the country?” Kokushibo was taken aback by Yoriichi’s newfound fluency in speaking. Subsequently, Yoriichi expressed his desire to become a samurai, which elicited his first smile, but Kokushibo only felt disgusted. He believes that a true samurai fights with the possibility of losing their life, and a child who seeks refuge in their mother could never become a man capable of such courage.
During Kokushibo’s training sessions, Yoriichi would frequently observe him until the teacher gave him some rudimentary directions. At that moment, Yoriichi managed to defeat the instructor with a blow despite being only seven years old. In contrast, Kokushibo was unable to strike his instructor’s body, regardless of how much effort he put in. Nonetheless, he lost consciousness after Yoriichi unleashed four rapid strikes in the blink of an eye.
Following that incident, Yoriichi never expressed his desire to become a samurai again because he could not bear the sensation of striking someone. However, Kokushibo was eager to learn the secret behind Yoriichi’s strength. Yoriichi disclosed that he could discern his opponent’s lung expansion before they attacked, allowing him to scrutinize their bone movement, muscle contraction, and blood flow carefully. Kokushibo realized that Yoriichi could see the inner workings of a living being’s body and had the physical power to react promptly to that knowledge. The boy he previously deemed pitiful was evidently mightier than he had ever imagined.
Yoriichi then suggested that instead of discussing the sword, he would prefer to play sugoroku and fly kites with Kokushibo. Kokushibo devoted himself to the sword, so he felt slighted by Yoriichi’s words. He believed that it would have been better if a deserving individual possessed the desired talent, but Yoriichi only appeared uninterested whenever the sword was discussed as viewed by Kokushibo.
Shortly after, Kokushibo started to overthink the possibility of their roles being reversed, with Yoriichi being the subordinate and himself being relocated to the three-tatami room while he would never achieve his dream of becoming a samurai if he were sent to the temple. However, at three o’clock in the morning, Yoriichi called Kokushibo outside his room to inform him that their mother had passed away. He then revealed to Kokushibo that he would be departing for the temple immediately and simply wished to bid farewell. Yoriichi also mentioned the flute that Kokushibo had gifted him and smiled as he stated that he would regard the flute as his brother. He promised that, despite the distance between them, he would never lose heart and would work diligently every day.
Yoriichi then lowered his head in contentment and then departed. Kokushibo failed to comprehend why Yoriichi was smiling since he considered the flute to be worthless. Once again, he found the situation disgusting and was unable to respond.
Afterward, Kokushibo discovered their mother’s diary and learned that Yoriichi knew that he would become the heir, so he departed their home earlier than intended. He also learned that Yoriichi had clung to their mother because she suffered from a condition that caused her left side to be in pain. Upon learning this, Kokushibo only felt envy and despised Yoriichi from the bottom of his heart.
Their father frequently dispatched emissaries to the temple to retrieve Yoriichi, but he had vanished without a trace. Kokushibo was not concerned about his brother’s whereabouts as he believed that his wish had came true. He lived a peaceful existence with his wife and children for a decade. However, one day, a demon attacked their encampment, and Kokushibo encountered Yoriichi once more.
Yoriichi rescued Kokushibo from a demon, and upon seeing Yoriichi’s immense power, Kokushibo’s peaceful existence was shattered. The envy and animosity that had previously simmered within him resurfaced once more. He coveted Yoriichi’s power and chose to abandon his home, wife, and children to embark on the same path as a demon hunter like Yoriichi.
Kokushibo received the Demon Slayer mark, but he was unable to employ the Breath of the Sun technique, so he created a derivative of it, which he dubbed the Breath of the Moon. Kokushibo eventually recognized that those with demon slayer marks were paying for their lives so that the demon’s era would soon come to a close. He felt hopeless since he was still unable to match Yoriichi’s level. It was then that Muzan approached him and offered him the chance to become a demon so that he could live eternally. Kokushibo accepted the proposal since it provided him with the opportunity he had always yearned for, and he was freed from all of his obligations. Kokushibo expresses that individuals who do not feel jealous of others are merely fortunate since they have not encountered someone who has been entirely favored by the gods.
Upper Moon 2: Doma
Chapter 142 introduced Doma, who was born with unique features – rainbow-colored eyes and pure white oak hair. Doma’s parents were convinced that he had a divine ability to hear the voices of gods, leading them to establish the Eternal Paradise Cult centered around him. However, Doma did not possess this ability and found it absurd that grown adults believed in it and worshipped him. He considered them crazy for believing in fairy tales, as he did not believe in paradise himself. Despite this, Doma discovered a sense of purpose in making unhappy people happy.
Moving ahead to chapter 163, Doma’s mother discovered that his father “kept putting his hands” on the followers of the cult. In response, she became enraged and stabbed him multiple times before taking her own life with poison. Despite this traumatic event, Doma did not exhibit any feelings of shock, sadness, or trauma. His initial reaction was to criticize the mess in the room, and he simply crossed his arms and stood there in front of the deceased bodies. Doma displayed a lack of empathy and emotional detachment from normal human emotions, which was a characteristic he had exhibited even before becoming a demon. He had always demonstrated sociopathic tendencies, never experiencing emotions such as sadness or loneliness.
Once he met Muzan, he became a demon at the age of 20 and lived for several centuries. Doma had never believed in an afterlife or paradise, and as a result, he developed a disturbing belief that people could live forever through him after he consumed them. He believed that since death was a common fear, he could save people from suffering by devouring them. Doma used his cult to attract female followers whom he would manipulate and ultimately consume. His lack of empathy and remorse towards his victims was unsettling, but he found satisfaction in the belief that he was offering salvation to these women. This pattern of behavior continued for generations.
Doma also preyed on Inosuke’s mother, Kotoha, who was just 17 or 18 years old and sought refuge from her abusive husband in the Eternal Paradise Cult with her baby. After enduring daily beatings, Kotoha had no family or friends to turn to for help. Despite suffering severe injuries that left her blind in one eye and with a swollen face, Doma found herself beautiful once she had healed.
Doma claimed that he had no intention of consuming Inosuke’s mother because he enjoyed having her as a member of the cult. However, Kotoha eventually discovered that Doma was secretly devouring female followers and decided to flee. Fearing that Kotoha would expose his true nature, Doma pursued and trapped her in the woods, ultimately killing her. But before her death, Kotoha attempted to save her baby Inosuke, by throwing him off a cliff and into a body of water, hoping he would survive instead of becoming Doma’s prey.
Doma believed that the baby had perished in the fall, but to his surprise, the child survived and was nurtured by wild boars in the wilderness. Doma expressed no remorse for his actions towards Kotoha and even boasted about it to Inosuke during the Infinity Castle Arc. Doma is notorious for preying on women, particularly pregnant ones, as he believes they provide more nourishment due to carrying a baby. He puts on a facade of treating the other Upper Moons as dear allies, but this is far from the truth. In reality, some Upper Moons, such as Akaza, despise him for his behavior.
Upper Moon 3: Akaza
In chapters 154 to 155, we get to know about Akaza’s backstory. Akaza endured a poor life with his ailing father. At the tender age of eleven, he resorted to stealing wallets to afford his father’s medication. Despite being caught several times, Akaza persevered and grew stronger as he attempted to escape every capture.
After being apprehended and brought before a magistrate, Akaza received three pickpocket tattoo lines instead of cutting his wrists as a sign of mercy. He adamantly protested to the magistrate that if his wrists were cut off, he would still have his feet and would continue to pickpocket with them. This defiance earned him the label of “demon child.” Akaza accepted this label as he had been born with fangs.
Following a beating during one of his thieving attempts, an elderly man approached Akaza and delivered the heartbreaking news that his father had taken his own life after learning of Akaza’s capture. The man presented Akaza with a suicide note written by his father, which read:
Upon learning of his father’s tragic demise, Akaza wept before his father’s grave. However, instead of heeding his father’s words, he persisted as a ruthless individual. The cycle of stealing and getting into fights continued, resulting in his capture and punishment by the magistrate. He endured beatings to the point of his bones breaking. Despite the pain, Akaza remained determined to obtain his father’s medicine, willing to endure any suffering for as long as it took, even if it meant risking his life.
Amid one of his scuffles with a local community, a dojo master took notice of Akaza’s impressive physical strength and ability to overpower adults without a weapon. The master invited Akaza to become his sole student, but Akaza responded with cursing and threats of violence. The master acknowledged the tattoos on Akaza’s body, recognizing them as symbols of his criminal past during the Edo period. He challenged Akaza to a fight but Akaza ultimately lost. After this, Akaza accepted the invitation and began to live with the dojo master.
It is eventually revealed that the dojo master’s name is Keizou, and he instructs the Soryuu martial arts dojo, specializing in bare-fist fighting techniques. Keizou confides in Akaza that he has no other students due to individuals who sought to take over the dojo frequently harassing him.
Keizou appeals to Akaza to care for his sick daughter since his wife had drowned herself to not see their daughter die. Akaza marvels at Keizou’s trust in him despite his criminal background, to which Keizou jokingly retorts that he had already beaten Akaza up a few hours earlier, and thus everything was fine.
The moment Akaza laid eyes on Keizou’s daughter, Koyuki, he immediately saw his own father in her. Koyuki’s frail body required Akaza’s constant care and attention. Together, they shared tender moments, such as when Koyuki encourages Akaza to watch the fireworks without her while she recuperates from her dizziness. Nevertheless, Akaza pledges to wait until she feels better so that they can watch the fireworks together on the bridge. Akaza reassures Koyuki that there will always be fireworks every year, and he prefers to witness them with her. These words bring tears to Koyuki’s eyes.
Later on, it is revealed that Akaza’s real name in his human life is Hakuji. Akaza reflects that his training under Keizou and caring for Koyuki had helped to heal his heart. As Koyuki turned 16 and regained her health, she was able to live a normal life once more. Keizou approached Akaza and asked if he would be willing to take over the dojo and also have Koyuki as his own. This proposal left Akaza and Koyuki blushing with one another.
Given his troubled past, Akaza had never envisioned a future for himself, let alone one where he could be loved by another. He began to ponder whether his father’s words may have been right after all. At that instant, Akaza felt a deep desire to protect both Keizou and Koyuki, even if it meant sacrificing his own life.
One day when Koyuki was visiting his father’s grave, an old man informed Akaza that someone had poisoned the well as an act of revenge against Keizou. Even Koyuki herself had been killed in the process. Akaza was left speechless by the news, realizing that whenever those he cared about were in danger, he had never been present to protect them.
As Akaza reminisced about his cherished memories with Koyuki beneath the fireworks where she suddenly proposed to him. The joyous moment triggered a traumatic reaction in Akaza, causing revert to his former violent behavior. Fueled by rage, Akaza launched a vicious attack on a nearby kenjutsu dojo. In a gruesome display of violence, he brutally murdered sixty-seven students with his bare fists, crushing their skulls and smashing their insides. The resulting carnage was so severe that the corpses were unrecognizable, their forms scattered across the ceilings and walls.
The sheer absurdity and incredibility of the event led it to be dismissed as a fictitious account for thirty years until it was eventually erased. As Akaza walked away from the scene, drenched in blood, Muzan appeared before him. Muzan was surprised, as he had no memory of dispatching any demons to the area, yet he had heard reports of a demon sighting. Disappointed to discover that it was only a human responsible for the mayhem, Muzan decided to transform Akaza into a powerful demon, causing him to lose all memory of his past due to the traumatic events he had experienced.
Read more: Is Demon Slayer: Kimetsu No Yaiba Over?
Upper Moon 4: Nakime
Nakime’s origin story is not revealed in the manga itself but rather in the second Demon Slayer fan book. According to the fan book, Nakime was a biwa player who faced financial difficulties due to her obscure status as a performer and her husband’s gambling addiction, which frequently left them destitute. One day, in a fit of rage, her husband sold her only kimono to finance his habit, and Nakime responded by using a hammer to fatally bludgeon him.
Despite her hardships, Nakime persisted in performing, wearing her worn-out kimono and enduring the disapproving glances of her audience. Nevertheless, when she played the biwa with her trembling hands, her skill was applauded. She came to the realization that committing murder just before a performance enhanced her biwa playing abilities significantly. As a result, she began to take lives before every performance.
In an attempt to augment her musical talent, Nakime plotted to assassinate the wrong person, Muzan, so her plan ultimately failed. Nonetheless, Muzan was so impressed by her audacity that he transformed her into a Demon, endowing her with unparalleled musical skills and extraordinary powers.
Former Upper Moon 4: Hantengu
In the manga’s 126th chapter, as Tanjiro concludes his battle against Hantengu, Hantengu experiences a flashback of his life on a single page. Hantengu, who had been a deceitful liar, consistently fabricated excuses to portray himself as a victim while demonizing others. He was a skilled manipulator who had a victim mentality and frequently swindled money from the visually impaired. He even went to the extent of blaming his own hands as if they were beyond his control. Despite his delusions of innocence, Hantengu was a heartless criminal who committed theft and murder in various towns.
The magistrate sentenced Hantengu to amputate his arms, but Muzan came to him with an offer to transform him into a demon, which he accepted. After escaping from prison as a demon, Hantengu sought revenge against the magistrate who had condemned him to death. The magistrate warned Hantengu that his excuses would never change the truth and threatened that one day; he would pay for his sins with his own life. In the Swordsmith Village Arc, Hantengu faced the consequences of his actions, and the magistrate’s words rang true.
Upper Moon 5: Gyokko
The second Demon Slayer Fanbook sheds light on Gyuokko’s past, as the manga does not provide much information. Gyuokko, also known as Managi, lived on the outskirts of a fishing village, where he was an outcast due to his odd behavior, such as collecting fish remains and partaking in other unusual activities. His parents were fishermen who went missing during a fishing expedition, and their severely mutilated corpses were found later, piquing Gyuokko’s interest in their aesthetic.
A village child provoked Gyuokko, causing him to lose control and murder the child, which he preserved in a container. As a result, the child’s parents attacked Gyuokko with a fishing fork, intending to kill him. However, Muzan was passing by and decided to transform Gyuokko into a demon.
Upon becoming a demon, Gyuokko acquired a fondness for human flesh, particularly that of children, and modified his physique to fulfill his cravings. He held a strong contempt for all living beings except for Muzan, whom he idolized. Gyuokko took delight in mocking and jeering at those in his vicinity, relishing in his newfound strength and animosity towards humanity.
Upper Moon 6: Kaigaku
In Chapter 145, Kaigaku’s impoverished lifestyle was depicted, where he resorted to drinking dirty water from the ground or stealing money to make ends meet. He justified to himself that it wouldn’t be a defeat unless he died.
During Episode 17 of Season 1, Jigoro took Kaigaku under his wing to train him as a demon slayer. However, during their training sessions, Kaigaku frequently insulted Zenitsu by referring to him as a crybaby and stating that he was a waste of Jigoro‘s time. This conduct may have played a role in Zenitsu’s diminished self-worth and absence of assurance.
Kaigaku possessed proficiency in all thunder breathing techniques except for the first and most crucial form, he faced ridicule from other demon slayers who anticipated his demise due to this deficiency.
During his mission, Kaigaku comes across Kokushibo and realizes that he lacks the strength to overcome him. He kneels down and surrenders to Kokushibo, with his sword placed beneath his head. This decision stemmed from his strong resolve to never die, even if it meant disregarding Jigoro, who had taken care of him and provided him with nourishing food.
Kokushibo saw potential in Kaigaku and decided to offer him blood extracted from Muzan’s cells. Despite being aware of the demon slayers’ code of conduct and the potential repercussions on Jigoro, Kaigaku accepted the offer.
Prior to consuming the blood, Kokushibo advised Kaigaku that attaining immense strength as a demon requires time and urged him to appreciate the blood he was receiving. Kokushibo instructed him to avoid spilling a single drop, and, despite experiencing fear so intense that even his cells were screaming and crying, Kaigaku drank all the blood. As a result, he underwent a transformation into a formidable demon who has a breathing style much like Kokushibo.
Former Upper Moon 6: Daki and Gyutaro
In the 96th chapter of Demon Slayer, as the brother and sister began to fade away, Daki uttered her final words, “Onii..” before disintegrating into ashes. Gyutaro was left with a single eye staring at the empty space where his sister had been. Memories of their past flooded his mind, including the fact that Daki’s true name was “Ume,” the same name as the disease that claimed their mother’s life.
Born into poverty in the Rashoumongashi red-light district, the siblings’ mother attempted suicide multiple times after Gyutaro’s birth. Despite his arrival, Gyutaro was regarded as nothing but a burden, with his mother even trying to end his life on several occasions. Nonetheless, Gyutaro managed to survive.
Despite having a frail body, Gyutaro struggled to stay alive and was frequently ridiculed by the community. He was mocked for his unappealing appearance and unattractive voice, being called names like “maggot,” “coward,” and “useless.” Gyutaro recounts how, as a young child, he was often covered in dirt and dandruff, and infested with fleas, leading to a noticeable odor.
In the red-light district, where physical attractiveness was highly valued, Gyutaro was treated with contempt like a grotesque creature. When hungry, he resorted to eating rats and insects, and his only toy was a sickle that a customer had left behind. However, everything began to change when Ume was born.
Ume was the source of Gyutaro’s happiness, and he took great pride in her stunning appearance, which even made adults pause in admiration. Recognizing his fighting skills, Gyutaro started working as a money collector and found a sense of fulfillment, even though his “ugliness” made him feared by many. Instead of being ashamed, his unique appearance became a source of pride. Together with Gyutaro’s strength and Ume’s beauty, he believed they could propel themselves toward a better life for the first time.
When Ume reached the age of thirteen, she blinded a samurai by stabbing his eye with a hairpin. As revenge, Ume was bound and set on fire, burning her to death. At the time, Gyutaro was away at work, and upon his return, he found his sister’s charred body barely clinging to life. He cried out, holding her in his arms, pleading for her to return to normal and cursing the gods if she didn’t.
Without warning, the samurai appeared and mercilessly attacked Gyutaro, knocking him to the ground. Despite the brutal beating, Gyutaro’s impressive combat abilities allowed him to put up a formidable resistance. In a fierce final showdown, he used his sickle to slice the samurai’s head in two. Following this, Gyutaro carried his sister in his arms, hoping to find help from anyone, but nobody came to their aid. It dawned on him that this had always been the case — the people who were willing to help them simply did not exist.
As snow fell heavily, the siblings found themselves on the brink of death from the cold. Gyutaro had lost all hope until Doma, the second-highest-ranking demon of the twelve moons, appeared before them, clutching a dismembered woman’s body. Doma claimed that he couldn’t leave the pair alone, calling himself a “nice guy.” He then presented himself as a benevolent demon, offering to give them his blood, which would turn them into demons if chosen by Muzan.
Despite the irony of consuming human life, Doma stressed the value of existence, stating that life is precious. He extended his hand, asking if they would like to join the ranks of the twelve demon moons and ascend to an Upper Moon.
Gyutaro had no regrets about becoming a demon, vowing to do so even if he had to be reborn countless times. He harbored a deep resentment towards those who had better lives than him and vowed to become a pimp, snatching away their happiness and collecting them for himself.
Hovering between life and death, Gyutaro reflects on how his sister, Ume, could have had a different life if circumstances had been different. Had she been raised by another family, she could have been a proper Oiran or even just a normal girl. Gyutaro is tormented by the thought that he was the one who taught Ume to “take before you’re taken, and collect,” leading her down a destructive path. He wonders if things would have been different had Ume remained obedient to the samurai. Ultimately, Gyutaro’s only regret was the fate of his beloved sister.