Tanjiro braces himself for death, when Rui unravels his Blood Demon Art.
As his life flashes before his eyes, he remembers his father's kagura dance and unleashes a whole new technique, completely different from Water Breathing. Hinokami Kagura: Dance... Knowing that this move could mean killing each other, he uses his new move to slice off Rui's head.
As Tanjiro crawls towards Nezuko, who lies on the ground, riddled with wounds, someone appears before him…
In a combined effort using Hinokami Kagura and Exploding Blood, Tanjiro and Nezuko defeat Lower Rank Five, Rui. As the demon’s body falls, Tanjiro collapses in exhaustion, while Nezuko’s body lands on the ground, having burned away her restraints. He knows he had succeeded thanks to his father’s Kagura, yet he remains unsure how its memory had helped him beat Rui. His vision blurs from pushing himself to the brink and his body is in physical agony. He slowly crawls to his sister and remembers that Inosuke still needs help.
Suddenly, he detects the scent of blood from behind him, noting that he doesn’t smell ash; the scent present during a demon’s death. To his horror, he hears something walking toward him, despite believing he had decapitated him. Rui taunts him for believing he had won, revealing he cut off his head using his threads to avoid dying. Now deciding to kill both of the siblings, he exclaims he hasn't been this enraged in a long time. As he attempts to crawl away faster, Tanjiro tries to get his breathing under control. Rui mentions that he doesn’t know why Tanjiro didn’t get burned by Nezuko’s flames when he and his threads but doesn’t dwell on it.
Angered, Rui declares he can now carve him to pieces without a second thought. As Tanjiro thinks using the right technique can help him despite being exhausted, Lower Five draws a web in his hands and uses Blood Demon Art: Murderous Eye Basket. Blood threads begin to encircle Tanjiro; he desperately tries to calm himself and use his breathing technique but finds he is unable to even raise his arm.
As the threads close in on him, they slice both his hands and shred his uniform. Before Tanjiro can be killed, Giyu enters the battle and slices apart the blood thread web, saving him. As Tanjiro weakly sees someone has saved him, believing it to be Zenitsu, Giyu commends him for holding on till his arrival, leaving the battle to him. Seeing him, Rui angrily denounces the Demon Slayers as “an endless stream of lowlifes always getting in my way”. Using Blood Demon Art: Cutting Thread Rotation, he forms a spinning web of blood threads and launches it at his attacker.
Giyu responds with Water Breathing, Eleventh Form: Dead Calm and ceases all movement. As Tanjiro watches, not knowing an eleventh form existed, Rui deems his technique irrelevant. As the rotating web reaches Giyu, it suddenly breaks apart before it can hit him. Confused, since he wasn’t moving when the attack got to him, the demon tries again but is easily decapitated by the Hashira in the time he's blinked.
Elsewhere, Daughter continues to run away, muttering that this is the only time she had messed up in her role in Rui’s pretend family. She remembers the time when she first met the Lower Rank; she had been chased by several Demon Slayers and cornered at a large house in a clearing. As they prepared to kill her, they see another demon on the roof, Rui himself. He spoke to her and asked if she wanted him to save her, asking her to obey his wishes in return. She quickly agreed to his offer; to become a part of his family. As the Demon Slayers close in on them, Rui takes hold of several threads within the clearing, slicing them to pieces. As she looks behind her, seeing her assailants now dead, she hears something within the house; a large group of spider-like demons. The Lower Rank takes her hand and welcomes the new demon.
Inside the house, her initiation to join begins, with Rui and one of his older sisters present. As the most powerful demon in the house, he is the one to give strength to the others through his blood. Using a thread, he draws a drop of blood and adds it into a solution to be drunk. Daughter is offered the liquid by her new sister, who adds that Rui is allowed to share his strength being one of “that person's" favourites. After taking it, Daughter is suddenly racked with intense pain as the Lower Rank’s blood begins to affect her; Rui asks if she feels it, stating she no longer needs to fear the Demon Slayers. He then gives the “finishing touches”, grabbing the demon’s face and ripping it off as she screams in agony.
At the end of her initiation, Daughter sees her appearance has now changed, with Rui congratulating her and recognizing the demon as part of his family now. In her first family "dinner”, everyone sits down in a candle-lit room and pretends to partake in a meal, with Rui satisfied by the feeling of family. Later on, Daughter’s older sister informs her they all have no blood ties and are all strangers to one another. Outside, she sees Rui torturing a young demon. She apologizes to him and claims she will do better, telling him it is only accidental she reverts to her usual appearance. Instead, the Lower Rank ties a thread to her neck in anger, causing her to bleed. He eventually releases his hold and mutters, “I don’t want to hear your excuses, Mother”, as she transforms back into her spider-like appearance; he tells Mother to play her given role as she should and she quietly obeys his orders.
Her sister states they were all scared of the Demon Slayers and simply wanted company, and that they never wanted to be part of his “family”. But those who disobeyed him were met with severe reprimanding. She claims she has had enough of playing his game and offers a plan to escape with Daughter, claiming she is the only one she doesn’t see as foolish and recognizing her as a real sister. The next day, when Rui is summoned by Muzan to descend the mountain, Daughter and her sister run away together to escape the forest.
As they make their way down the mountain, they are met by Rui standing in their path; fearing the consequences, Daughter leaves her sister’s side and stands with him. In retaliation, Rui slices his older sister throughout her body with his threads, leaving her restrained at the top of the house to burn in the sunlight. Seeing her bloody body strewn with slashes from head to toe, he only mutters his disappointment in her and coldly walks away, with Daughter following him. As dawn breaks, the demon is hit by sunlight and subsequently burns to death.
Daughter remembers that day, admonishing her and all her deceased family members as fools. Regardless, she acknowledges her own mistake, reminiscing on the moment she last met with Rui. She informs him that both Mother and their older brother have been killed, with the Demon Slayers closing in on them. As she proposes they escape, her eyes change back slightly to their original look. Rui notices this and angrily slashes her face, reminding her of his dislike when it happens, leading to Tanjiro’s confrontation with him. As she continues to run through the forest, she catches sight of a Demon Slayer. Murata sees Daughter but she quickly encases him in a web cocoon before he could attack. He tries to stab through but fails to cut the silk; to his shock, acid begins to seep through the silk. She describes how it will dissolve his clothes first, then his body, and she will then devour the remains afterwards.
In an instant, Shinobu appears behind her, asking if her silk comes through her palms. In shock, Daughter stands in silence as Shinobu bids the demon “Good Evening”, commenting on the moon’s appearance. She quickly launches ropes of silk at the Hashira but Shinobu skilfully evades her attack and pins her to the ground. Shinobu sees she has no intention to befriend her; Daughter begs her to listen and claims she is being forced by “him”, stating she will be killed if she disobeys his orders. Shinobu seemingly accepts her plea and offers to spare her, only to add that she must ask her a question beforehand.
Shinobu calmly asks how many people she's killed; frightened, Daughter quietly answers, “Five”, as she begins to tear up, stating she was ordered to do so. Shinobu tells the demon she does not need to lie, as she already knows how many. She comments on the impressive attack that is her cocoons and claims that she has devoured at least eighty people. Daughter denies this and repeats she only killed five. Shinobu then informs her that as she came from west of the mountain, she saw hordes of cocoons in the trees, mentioning she counted fourteen in one spot alone, all human captives now dead.
The Hashira states she isn’t angry but simply getting an accurate toll; Daughter asks what good will it be to be accurate and Shinobu states it is for her to get the proper penalty, “so you and I can become friends”. She threatens to gouge out her eyeballs, disembowel her body and torture her for each of her victims, and that only after suffering will she be forgiven. Horrified, the demon begins to panic, and Shinobu slyly replies she won’t die being a demon.
Daughter attacks her with a wave of silk but Shinobu easily evades the attack, pitying her and their inability to become friends. When she attempts to attack again, she sees Shinobu has vanished. Daughter looks up and sees Shinobu lunging at her from the sky; as she gets close, the demon suddenly sees herself engulfed in a flutter of butterflies. One lands on her finger but it begins to bleed, with her body suddenly bleeding as well. Shinobu has attacked Daughter with Insect Breathing, Butterfly Dance: Caprice. Daughter grabs her neck but sees that she isn't beheaded, noticing her blade isn’t shaped to cut and concluding she is too weak to behead demons.
As she sees Shinobu as someone she can beat, her body suddenly changes; blood vessels burst and her body begins to convulse. Finally, Daughter is hit by a sudden wave of pain and falls over. Hearing the body slump to the ground, Shinobu tells her not to feel safe when realizing she isn’t beheaded, as there are Demon Slayers who use poison. Twirling her blade in a display of skill, she states that of the Demon Slayer Corps, she is “Insect Hashira, Shinobu Kocho”; despite being the only one unable to behead demons, she is still “rather awesome” for using poison to kill.
Shinobu cuts open Daughter’s last cocoon, freeing and saving Murata. He asks if she will finish off the demon but Shinobu states she is already dead from her wisteria poison. She happily notes that while Murata’s clothes have dissolved, his body is unscathed, leading him to slink away in embarrassment. She then turns her attention to the demon supposedly forcing Daughter, wondering if Giyu had beaten her to it.
As Tanjiro makes his way to Nezuko, Rui’s severed head falls, still wanting to kill the siblings. Internally, he sees Mother asking what are his intentions with his “family”. He states he isn’t sure but that he has no human memories. Mother asks if that is why he made them pretend to be his. Rui believed he could regain them if he felt a familial bond. He sees Tanjiro hugging Nezuko and realizes he did everything to get what they have.
Characters in Order of Appearance
- The anime goes more into detail of the Spider Family's origin as well as showing one of the Older Sister Spider Demon's memories which was not depicted in the manga.