Daki/Synopsis

Human Life
Daki was born over a century ago into poverty with the given name "Ume" in the Entertainment District's Kirimise/Rashomongasi (Lowest Caste) area, where sick prostitutes and geishas, along with oirans who could no longer work in the brothels, were sent and left to die. Her birth mother was a prostitute there, having given birth to her elder brother a few years before. Her biological father is never mentioned, but was likely one of her mother's customers. Her brother noted their mother to be severely mentally unstable (most likely due to the district's extremely harsh living conditions), having attempted to kill herself and her son numerous times. She also physically abused him due to not having the finances to keep him fed, forcing him to fend for himself. When Ume was born, their mother hated her due to her hair color and eyes and would try and kill her. One day, their mother tried to cut Ume’s hair off with a razor, but Gyutaro became enraged and went on a rampage, leading her to distance herself from her children. Ume was primarily raised by her elder brother until her early teen years, when her mother passed away from syphilis, the same sickness she was then named after.

Gyutaro noted that, even as a young child, Ume had an incredibly beautiful face that even grown men and women would falter from looking at. She was so beautiful that if she smiled, she would be given things, earning her the nickname Shiraume. This gave him hope that she could be recruited by a prestigious brothel and give them a chance to rise from poverty and lead a better life. This hope became reality in Ume's teen years when she was chosen to work in one of the Entertainment District's High Class Brothels. To train her as a Oiran, she was given a proper education, and fed the finest foods. While she was still in the training stage, Ume had begun making a fortune by attracting suitors and customers to the brothel with just her looks. At the same time, her elder brother began working as her "Collector" and would collect money and debts owed to the brothel.

However, this all came to an end when Ume stabbed a samurai costumer of hers in the eye when he insulted her brother. In retaliation, she was bound, burned alive and left to die in a ditch. Barely clinging to life, she was then discovered by her brother as he returned from collecting debts. He began to hysterically panic upon seeing her near-death state and was discovered by the samurai Ume wounded and the Manager of the House she worked in. The two attempted to kill the siblings, only to be killed by Gyutaro first, who then picked up his sister’s charred body and carried her around town in search of help. His struggle turned out to be in vain, as he came to the realization that no one would help them.

As Gyutaro collapsed from exhaustion and fatigue from his wounds, Doma, who was Upper Rank Six at the time, happened upon the siblings while wandering the district in search of beautiful Geishas to devour. Taking pity on them, he offered to help the pair by turning them into demons, claiming that it was because he was a "nice guy". He then challenged them to become strong enough to be chosen by Muzan Kibutsuji and join the Twelve Kizuki alongside him.

Demon Life
As a demon, Daki continued her work in Yoshiwara, at least dating back to the Edo Era, and gained a reputation for both her beauty and her malice, such that some of the elders remembered her ill-temper and demanded for "hime" (meaning "princess") to be added to her name. In an effort to disguise her identity as a demon, she held different names over the years such as Yatamahime and moved to a new house every decade. However, her personality was the same wherever she went, so as she moved around, her existence eventually became an urban legend. People would pass along stories of beautiful and cruel oirans with "hime" at the end of their names who slanted their heads to the side when angered, but no one actually knew all those oirans were one and the same.

As the years passed by, Daki fought, killed, and ate seven Hashira. At some point after this, she became a member of the Kyogoku House and held the name Warabihime. She became an Oiran and was known as the main source of the house's success. Despite this, her vicious nature became apparent and most of the staff greatly feared her. Her violent reputation was cause for several girls to commit Ashinuke, while others got hurt for annoying her and even committed suicide over her excessive bullying.

Two days before Tanjiro Kamado and his fellow Demon Slayers infiltrated the Entertainment District, Daki was confronted by Omitsu, the manager of the Kyogoku House, over her abusive treatment of the staff. When the hostess revealed her knowledge of Daki's past and attempted to kill her with a knife, the demon seized her and carried her far above the district. With no one around to hear them, Daki then mocked Omitsu for her stupidity, labeled her as inedible due to her old age, and dropped her to her death.

Upon returning to her room, Daki was surprised to see Muzan waiting for her inside. Bowing to her master, she listened as he praised her for her new-found strength, cautioned her against getting careless, and stated his high hopes for her as a special demon. Presumably during the same meeting, Muzan embraced Daki in his arms and gave her the task of hunting down and killing Nezuko Kamado, a demon that escaped his control just like Tamayo had.

Entertainment District Arc
Walking with several assistants, Daki passed under Tengen Uzui's watchful gaze undetected in her oiran guise. Later, using her sash, she questioned Makio about the letters she had been sending. Sensing Inosuke Hashibira's presence, Daki's sash fled.

Daki appeared behind Zenitsu Agatsuma as Warabihime, demanding to know what he was doing in someone else's room, and quickly grew irritated at his lack of a response. She extended this irritation to two girls who tried to defend Zenitsu, insulting the young Demon Slayer before viciously abusing a crying girl for not cleaning a room fast enough. Her anger grew as Zenitsu grabbed her wrist to stop her cruelty.

Daki hit the youth through several walls, threatening him with further discipline, but stopped when the master of the brothel begged her to. Apologizing to him, she ordered Zenitsu's wounds to be treated and the mess from her fit of anger cleaned up. The Upper Rank then pondered over Zenitsu's identity, noting he might be a Demon Slayer. Later, in her room, she gloated over the success of her plan, promising to kill and eat all of her enemies.

Daki then appeared behind Koinatsu, seeking to eat her before she left to be married. She was then confronted by Tanjiro Kamado while restraining her fellow oiran and questioned him about the amount of backup he had, including when the Hashira would arrive. Dismissing the youth for his weakness, Daki soon grew enraged when he demanded she release Koinatsu and attacked the Demon Slayer with her sashes. When he survived, she complimented Tanjiro's eyes, wishing to eat them. She briefly clashed with him again, noting his skill in only severing the section of sash containing Koinatsu, but confidently proclaimed his doom regardless.

She then expressed irritation at her foes' interference, asking Tanjiro about his backup again. Despite his refusal to talk, she offered to let him live if he told her, noting that in their brief clash his sword had been chipped. She also stated that whoever had forged the blade was a terrible blacksmith, and quickly grew irritated once more when her opponent denied this, promising to kill him with her next attack. Launching said attack, Daki was shocked when Tanjiro cut through her sashes with a Hinokami Kagura technique. Noting the change in his sword style, she dodged his next attack, countering with an attack of her own. Missing due to another Hinokami Kagura technique, the Upper Rank turned to face her opponent just as his blade struck her neck.

Before Tanjiro's blade can connect with Daki's head, the Upper Rank deflects his attack and sends him flying while remarking that Tanjiro's slow movements bore her. Tanjiro attempts to prepare another attack but fails because of exhaustion, leaving him open to Daki. She quickly approaches him while Tanjiro manages to recover and narrowly avoid her attack. Daki and Tanjiro continue to clash, while the Upper Rank remarks that Tanjiro's persistence is making the battle fun. As breaths fumes out of Tanjiro's mouth, the Demon Slayer chargers forward, to which Daki says repulsive things are still repulsive even if they try their best.

While a battle rages on between Inosuke Hashibira and one of Daki's sentient flesh Obi, Daki commands it to capture Inosuke alive and tells the sash to eat as many humans as it wants (except the ten prettiest ones) to strengthen its own power to fend off Inosuke. After the battle continues for a while, Tengen Uzui arrives and quickly subdues the sentient flesh Obi, which returns to Daki while she fights Tanjiro. Suddenly, Daki disappears as Tanjiro attempts to strike her, appearing on the roof of a nearby building while her hair turns white as she regains her full power. As a bystander berates Tanjiro for causing a ruckus, Daki unleashes a wide-ranged sash attack that destroys the nearby buildings and kills several civilians while also making a deep cut in Tanjiro's left shoulder.

Seeing the destruction she has caused, Daki contently walks away before Tanjiro yells out to her, to which the Upper Rank reacts in an expasarated manner, spewing that the lives of ugly humans have no value. Suddenly, Tanjiro appears behind Daki, grabbing her leg as he attacks her. Daki ducks and uses a sash to deflect the attack before jumping away, having her leg ripped off by an enraged Tanjiro in the process. Daki swiftly regrows her foot while recalling the similarity between Tanjiro's words and those of a swordsman she had never met. She realizes that she is experiencing the memories of her master left in her cells. After Tanjiro brings up Daki's human life, she punches a hole in the roof before saying that she doesn't remember her human life and being a demon in the present is all that matters. She continues saying that demons don't get sick, old, don't need money to eat, don't lose anything and that they can do whatever they want.

As Daki finishes speaking, Tanjiro rushes forward and Daki unleashes her Eight-Layered Obi Slash technique. Daki remarks to herself that her Obi has been spread across the city to take control of Yoshiwara, and now that the sashes have returned to her, she is much more powerful. Daki continues by saying since Tanjiro barely managed to survive while Daki wasn't at full power, its impossible for him to win and declares that she will cut him up along with his blade and head for the Hashira. Contrary to her expectations, Tanjiro uses Burning Bones, Summer Sun to slash up her sashes, dumbfounding Daki. As Tanjiro continues his relentless onslaught of sword slashes, Daki feels confused as to why he isn't feeling the pain of his injuries and is instead getting faster. Tanjiro's blade manages to reach Daki's neck, but the Upper Rank transmutes it into an Obi sash to lessen the effectiveness of his slash and prevent decapitation.

Realizing this, Tanjiro hops away while Daki tries to attack him with thirteen sashes. Tanjiro expertly parries all of them into the same spot, and pierces all of them into the ground. Daki arrogantly remarks that she will just simply blast him away, but realizes that Tanjiro has pulled them taut so they can't stretch and bend. Suddenly, Tanjiro backflips into the air and cuts up all of Daki's sashes before running up to her, poised to slash off her neck in an instant. Just then, Tanjiro collapses to the ground and starts violently coughing up blood. Seeing this, Daki remarks that humans are miserable before remarking that she will slice off his head.

Unbeknownst to her, Nezuko Kamado appears behind Daki and destroys a chunk of her head with a kick. Daki jumps away while restoring her head, before realizing that Nezuko was the demon Muzan told her to kill. Nezuko rushes forward and prepares to attack Daki, before the Upper Rank cuts off her leg and slices her torso in half, sending her flying into a nearby building. She mocks her for being weak and being a half developed demon, since she hasn't eaten any humans. Daki continues to provoke her and cockily says that she will not fight Nezuko anymore, and will instead absorb her and expose her to the sun to die. However before Daki can say anything else, Nezuko comes out from the rubble and regenerates her leg in an instant, leaving Daki stunned at her abilities. Nezuko proceeds to instantaneously regenerate her severed arm, leaving Daki uneasy as she realizes that her regenerative abilities have reached the level of an Upper Rank Demon.

Nezuko's body transforms as she breaks her bamboo muzzle, a horn growing out of the right side of her forehead and her body also becomes covered in ivy-like demon crests. Daki gets more intimidated by Nezuko's change in aura and she tries to defend herself from one of her kicks, successfully stopping off with her obi. However before she can cut Nezuko's head, Daki is still smashed into the ground by Nezuko's kick. Daki is shocked as Nezuko's leg pierces through her body, pinning her into the ground. She tries to make sense of how Nezuko could've attacked her with the leg she had just sliced off, but lately realizes that Nezuko regenerated her leg in that instant, making her regenerative abilities greater than her own.

As Daki remains pinned on the ground, she uses her Obi to try to free herself from Nezuko's hold. She effectively severs multiple limbs from Nezuko's body, but Nezuko's limbs grip her Obi, as they are connected by her unusually solidified blood. Some of the blood falls onto Daki, and she is set on fire by the blood causing her to scream out in agony. Nezuko's limbs wind back to reattach to her body and they self cauterize each cut, she proceeds to forcefully stomp down on Daki's head causing it to erupt in flames. Nezuko continues to stomp multiple times on her head before she kicks forcefully kicks Daki through multiple buildings.

As Tanjiro struggles to keep Nezuko from attacking, Daki barges into the room they are in with sections of her body burned off. She is seen seething with anger as she is forced to regenerate her burned body, and angrily approaches the siblings. Tanjiro becomes conflicted on what to do as he realizes that there are nearby bystanders he needs to protect, but also needs to defend Daki's attack without releasing Nezuko. As Tanjiro makes his decision to protect the public, Tengen Uzui appears before him and expresses his surprise at Nezuko's "flashy" demonization. Tengen goes on to comically berate Tanjiro for speaking highly of Nezuko's ability to restrain herself back at the Ubuyashiki estate, despite him struggling to restrain her now. Daki sees Tengen and excitedly reacts to Hashira arriving before her, but is coldly told to shut up. Tengen tells her to scram and says that she is too weak to be an Upper Rank demon. As that happens, Daki's decapitated head falls onto her lap, leaving her stunned as to what transpired.

Daki screams at Tengen for cutting her head off, and he responds by telling her to die quietly. The enraged demon reminds him that he had denied her Upper Rank status, which he affirms, but she proceeds to insist her status, much to his annoyance. To the Hashira's astonishment, Daki begins to throw a tantrum and cry, and he notes that she has been talking for far too long when she should have showed signs of dying. Still throwing her tantrum, Daki calls out to her elder brother to save her and a male demon begins to emerge from her body. Tengen senses the danger and attempts to immediately attack the two, but his blades hit nothing but air as the Demons disappear from his sight. On the other side of the room behind Tengen, Gyutaro comforts Daki, asking that she at least try to reattach her own head. Tengen wonders why Daki is still alive after being beheaded, as well as the presence of the new demon, who he comments as having great reaction speed. Gyutaro tells Daki to heal her burn, complimenting her good looks, and wounds Tengen when he attempts to attack them again. Daki tells her brother there are more demon slayers, asking he kill Nezuko who burned her and claiming she tried to do her best but "everyone got in my way and bullied me".

After Tengen causes an explosion, Daki protects her brother by forming an Obi sash around both their bodies, their bodies' unscathed as they confidently proclaim that they fight as one. In the present, Gyutaro notices the deterioration in Tengen's physical state and becomes gleeful when he realizes that his poison is slowly taking effect. Tengen proceeds to refute his claim saying that he is still in pristine condition and charges forward to attack the siblings. As they engage in a battle, Tengen manages to kick Daki away from Gyutaro and releases numerous dark beads which cause a cluster of explosions. As both sides reassess the situation, Daki is left whining as she pathetically reattaches her head to her body once again. As Daki finishes reattaching her head, she loudly doubts Tengen's words that the Demon Slayers will win by saying that they can't win since he has been poisoned, much to the horror of Tanjiro.

Gyutaro and Daki get riled up and reveal that they've eaten 15 and 7 Hashira respectively, and begin to attack the group. As Daki attempts to attack Tengen and Tanjiro from behind, Zenitsu bursts through the house within seconds to block the attack as Inosuke follows him. Now on the rooftop, Daki finally recognizes Zenitsu from the Kyogoku House and he demandingly commands her to apologize to the girl whom he had found crying earlier. She mocks his speech by revealing that women are treated like merchandise within the district and as the orian, she was allowed to do as she pleased with other people since she was the main breadwinner of the house. When she looks up at Zenitsu, a third eye appears on Daki's forehead revealing that Gyutaro can see them via her new eye.

As the battle continues, Daki and Gyutaro coordinate attacks to drive the Demon Slayers into a corner. As Tanjiro was about to leap down a roof of a building to assist Tengen, a voice can be heard telling them to watch out as Inosuke and Zenitsu crash onto the roof while fighting the Obi. Inosuke and Zenitsu ask Tanjiro for help in order to defeat Daki, and agrees asking that they finish quickly in order to help Tengen. Hinatsuru tells the boys that she will hide quickly in order to allow them to focus on the battle, and disappears as they face Daki. She gets excited when Tanjiro joins their fight and informs his comrades that they need a fast attack in order to cut her neck. Inosuke realizes that she has slowed down and decides to go first to attack as Zenitsu agrees with Tanjiro to protect him from behind. Inosuke proceeds to dash forward using Beast Breathing, Eighth Fang: Explosive Rush while Zenitsu and Tanjiro use Thunder Breathing, First Form: Thunderclap and Flash, Eightfold and Water Breathing, Third Form: Flowing Dance respectively, to protect Inosuke from the Obi.

Daki begins to crack under the pressure as Inosuke close in on her, and manages to draw both of his blades on either side of her neck. Inosuke buries his heels into the ground as he uses Beast Breathing, Sixth Fang: Palisade Bite to effectively decapitate Daki. Tanjiro smiles with joy as he witnesses Inosuke leap and catch Daki's head in the air, rejoicing at successfully cutting off her head. Inosuke claims they have to act fast and keep her head separated from her body. Having successfully decapitated Daki, Inosuke can be seen escaping with her head in order to prevent her from reattaching it to her body. He tells the other boys not to worry about him and to instead help Tengen, but before he can get to safety, Daki uses her hair to put up a resistance, which Inosuke easily repels. Before he can get away, Gyutaro appears behind him and impales him through the chest. Tanjiro looks on in horror as Gyutaro grabs Daki's head while Inosuke collapses on the roof.

As Tanjiro tries to behead Gyutaro after landing a surprise attack on him, Daki can be seen rushing to her feet at the sudden change of events to try to help her brother, but before she can get close to them, Zenitsu manages to free himself from the rubble. He attacks her by using Thunder Breathing, First Form: Thunderclap and Flash to bring her attention to him and then uses his Godspeed extension to quickly attack her neck. Zenitsu pleads with his blade to cut through her neck, since he was given the chance to escape the rubble and attack her while Gyutaro was subdued.

While Tanjiro and Tengen fend off Gyutaro and try to decapitate him, Daki can be seen resisting Zenitsu's attempt to decapitate her. She attempts to use her obi to kill Zenitsu at close range, but Inosuke unexpectedly rushes up revealing that he protected his heart from being stabbed by rearranging his organs. He also reveals that poison has no effect on him since he was raised on the mountains, before proceeding to assist Zenitsu in decapitating Daki. The three boys let out a roar as they muster out the strength to slice through the Demons necks. After the long battle, Zenitsu and Inosuke manage to decapitate Daki up on the rooftop while Tanjiro can be seen decapitating Gyutaro simultaneously on the ground. Her decapitated head then fell to the ground, facing the head of Gyutaro. As their heads began to disintegrate, Daki screamed at her brother, blaming him for their defeat and claiming that "an unsightly thing like [him] could never be her sibling," while Gyutaro retaliated that Daki was weak and did nothing to help. Saddened by the siblings' bickering, Tanjiro then stepped in, covering Gyutaro's mouth to stop him from screaming abuse at his sister and pleading with them to try and get along, as they only had each other left in the world. Daki began to cry, wailing that she didn't want to die; however, her head finally disintegrated, leaving Gyutaro alone. As Gyutaro began to remember their life before becoming demons, Daki appeared to him in her original form as Ume, asking him where they were going and to take her along with him. He initially rejected her, sharply telling her not to follow him. However, Ume suddenly embraced him tightly, apologizing for her past words and crying out that they were siblings and she would never let him go. The pair then departed to the afterlife, with Gyutaro carrying Daki on his back as he had always done before.