Tanjiro Kamado, Nezuko Kamado, Tamayo and Yushiro vs Susamaru and Yahaba

Tanjiro Kamado, Nezuko Kamado, Tamayo, and Yushiro vs Susamaru and Yahaba was a battle that took place in Asakusa, Tokyo. It focuses on the battle between Demon Slayer Tanjiro Kamado, Demons Nezuko Kamado, Tamayo, and Yushiro against Demons Susamaru and Yahaba.

Prologue
Infuriated by his encounter with a young Demon Slayer, Muzan Kibutsuji orders his two assassins to bring him the head of the hunter with hanafuda-like earrings. Susamaru and Yahaba both loyally agree to do so for their master and begin hunting for the said Demon Slayer.

Meanwhile, Yushiro takes Tanjiro and his sister to Tamayo's house, which has been cloaked by his Blindfold technique. Inside, they discuss Nezuko's condition and agree to become allies to take down Muzan and find a way to cure Demons.

Tamayo asks Tanjiro specifically to collect the blood of Demons closely related to Muzan so she can study it in hopes of developing a cure for Nezuko. Tanjiro agrees to let Tamayo test his sister's blood as well, in hopes that this cure can help all Demons return to normal if they so desire it.

Yahaba uses his Blood Demon Art to track Tanjiro and Yushiro's footsteps back to Tamayo's house. He tells Susamaru to begin the assault despite the house not being in clear view. Susamaru throws one of her temari through the talisman cloaking the house, revealing Tamayo's clinic. Tamayo and everyone inside are taken by surprise when temari balls start ricocheting and tearing the entire house apart.

The Assault Begins
Susamaru admits Yahaba was right about the hidden house while the latter finds himself confused due to sensing the Demon Slayer accompanied by several other Demons. Yahaba also tells Susamaru to attack more gracefully and with more maturity. The Temari Demon ignores her partner and lets her temari handballs go wild on Tamayo's clinic.

Tanjiro and Yushiro are both highly impressed by the Demon girls' strength and find themselves at the mercy of her temari while trying to protect Tamayo and Nezuko. Yushiro tries to shield Lady Tamayo from the flying temari but ends up getting his head completely destroyed by a ball that curves unnaturally through the air. Horrified, Tanjiro asks Nezuko to secure everyone else in the house and realizes that Susamaru is on an entirely different level than any other Demon he's dealt with before.

Susamaru notices Tanjiro through a large hole in the wall and recognizes him as the target Demon Slayer they're looking for. Tamayo asks him to fight back without worrying about herself and Yushiro because they're Demons and can heal. The Temari Demon continues her assault and Tanjiro knows the balls will just swerve if he tries to dodge. Instead, Tanjiro counters with the Water Breathing, Seventh Form: Drop Ripple Thrust, Curve.

Susamaru is impressed Tanjiro stabbed the temari at a curve to soften the blow. However, the temari can still move and flies off of Tanjiro's sword. Yushiro slowly regenerates his head and tells Lady Tamayo this is all Tanjiro's fault for blowing their cover. Yushiro says he'll never forgive the Demons for hurting Lady Tamayo. This amuses Susamaru, who takes off her kimono and grows four more arms. Wielding six temari this time, she promises to play with her new friends until they die.

While Yushiro focuses on protecting Tamayo while switching his spell to attack mode, Tanjiro tries deflecting the barrage of handballs flying through the house. He manages to cut two of them in half, but then the halves even attack him. Tanjiro realizes there are two demons attacking right now and he can smell them. Yushiro places a talisman on Tanjiro's head and reveals the Yahaba's arrows directing the temari through the air.

With his newly enlightened sight, Tanjiro is able to effectively avoid the temari. He asks Nezuko to take care of the arrow Demon hiding in the trees while he goes outside and confronts Susamaru directly. Susamaru notices his earrings and promises to take his head back to Muzan. She tosses six of her temari at him and the arrows guide them as they pursue Tanjiro around the outside of the house. He's able to dodge them using his advanced agility, but he's relying on Nezuko to disable the arrows guiding the temari balls. Nezuko finds Yahaba hiding in the top of the trees and kicks him, directing his focus away from the temari. The arrows guiding Susamaru's balls fade while Yahaba focuses on defending himself from several of Nezuko's kicks. Without the direction of the arrows, the Temari Demon's weapons stop in their tracks, giving Tanjiro the perfect opening to counterattack. The young Demon Slayer cuts all the temari in half and even manages to cut off Susamaru's arms with the Water Breathing, Third Form: Flowing Dance.

Tanjiro asks if both these Demons are closely related to Muzan, which Tamayo answers most likely. He emphatically promises to collect their blood in this fight. This amuses Susamaru, who dares him to try and extract blood from them. She refuses the Demon Slayer to displease her master. Irritated by Nezuko's filthy feet, Susamaru sends her flying with his Blood Demon Art. Susamaru instantly regenerates all of her arms and Nezuko crashes into Tanjiro. The Temari Demon tries everyone else fights the Temari Demon. Tanjiro puts his faith in Nezuko and they both rush toward their respective opponents.

Twelve Kizuki?
Tanjiro notices the opening thread on Yahaba's neck, but he's caught by his Blood Demon Art, Koketsu Arrow beneath his feet that snaps the thread and pushes Tanjiro back. He follows up with another arrow that sends Tanjiro flying into a tree. Yahaba barrages Tanjiro with several consecutive arrows that blast him all over, crashing him into everything in sight. Tanjiro is in grave pain and the Arrow Demon sends him high into the air and drops him from a height that will surely kill him. Tanjiro counters by blunting the crash with the Water Breathing, Eighth Form: Waterfall Basin.

At the same time, Susamaru tries to overwhelm Nezuko with her temari. Nezuko dodges and distracts Susamaru long enough for Yushiro to turn invisible and strike her down at close range. While she's reeling, Yushiro reveals himself and promises to make Susamaru suffer for hurting Lady Tamayo. This makes Yahaba realize that Tamayo is actually Tamayo the Fugitive and decides they should take her head back to Lord Muzan as well.

Susamaru recovers and throws three balls each at Yushiro and Nezuko, who are on both sides of her. Yushiro dodges but Nezuko tries to kick one of the balls back, only to get her leg chopped off as a result. Susamaru kicks Nezuko into the house and Tamayo rushes to her aid. Delighted, Susamaru asks if they can bring all their heads but Yahaba says they only need the Demon Slayer's and the fugitive's heads.

Weary from the battle, Tanjiro ponders his options against the exceptionally powerful Arrow Demon. This time, Yahaba attacks with arrows that chase Tanjiro around. The Demon Slayer can't even fight back using his sword because the arrows simply blast him away if the blade touches them. Tanjiro is blown back into a brick wall and momentarily drops his blade.

Yahaba tries to launch the young Demon Slayer into the air, but Tanjiro slips out of his kimono to avoid it. The Arrow Demon does, however, manage to wrap and arrow around Tanjiro's arm, threatening to twist it right off. Tanjiro uses his acrobatic skills to run up a tree and back flips quickly in the same direction as the arrow, unwrapping his arm from it.

Tanjiro figures that the only way he can win is by redirecting the arrows without touching them. Yahaba tries to finish the fight with more arrows, forcing Tanjiro to counter with the rotation of the fifth form to envelope the arrows. Then he uses the footwork of the third form to close in on Yahaba to combine both moves into the Water Breathing, Sixth Form: Twisting Whirlpool, Flowing Water. Using this, Tanjiro is able to stop the arrows from moving and absorbs their kinetic energy to fuel his next attack. Tanjiro unleashes the Water Breathing, Second Form: Improved, Lateral Water Wheel and severs Yahaba's head.

The Whirlpool technique normally loses force while not underwater, but the force of his attack was increased by Yahaba's arrows. Outraged by his impending death, Yahaba does his best to take Tanjiro with him to the grave. The Arrow Demon places several arrows on Tanjiro's body at once and they blast him away with more force than ever before. Tanjiro goes on the defensive by unleashing the Water Breathing, Fourth Form: Striking Tide to soften the blow against a brick wall. Another Kotetsu Arrow appears in Tanjiro pulling him high into the air with enough pressure to make it even harder for Tanjiro to unleash a Breathing Technique. This doesn't stop him as he uses the Water Breathing, Second Form: Water Wheel to disperse the arrow off of him. However another immediately appears pulling him downwards with him stopping it with the Water Breathing, Eighth Form: Waterfall Basin, then Water Surface Slash, Drop Ripple Thrust, Curve then Whirlpool.

Unleashing consecutive moves one after another puts intense strain on Tanjiro's body. He's able to hold out until Yabaha's head completely disintegrates and he falls to the ground exhausted. Tanjiro is too tired to even grip his katana and simply crawls in Nezuko's direction with his blade clasped between his teeth.

Nezuko, Tamayo, and Yushiro vs Susamaru
Susamaru kicks up a dust screen by bouncing her temari simultaneously on the ground over and over. She sends the temari hurling at Yushiro through the smoke, but he claims he can easily evade linear attacks without the guidance of the arrows. Yushiro turns invisible and tries to close in on his opponent, but Susamaru can see him thanks to the smokescreen.

The Temari Demon nearly takes off Yushiro's head again with a powerful throw when Nezuko suddenly reappears and kicks away the temari successfully this time. Yushiro watches in amazement as Nezuko manages to return all of Susamaru's powerful throws using her own kicks. Irritated, Susamaru challenges her to an intense kicking match where they exchange temari blows and kick the ball back and forth at incredible speeds.

Yushiro asks what Tamayo did to her, but the Doctor reveals she only used a healing serum made for demons. Nezuko is displaying her own physical strength and its growing rapidly. She even manages to kick the temari so hard that not even Susamaru can return it as it narrowly flies past her head and crushes the wall behind her.

Tamayo understands Susamaru is still holding back and decides she must decide this fight quickly. Before Susamaru tries to go all out on Nezuko, Tamayo confronts her and asks about her coward of a leader Muzan. She reveals the truth about Muzan's manipulation while casting an Enchanting Blood spell without her opponent noticing. Blood Demon Art, Blood Bewitchment: Magical Aroma of Daylight weakens Susamaru's brain function and she's tricked into invoking Muzan's name while telling Tamayo to stop disrespecting him.

Susamaru immediately realizes her mistake and begs for forgiveness. However, Muzan's curse cruelly destroys Susamaru's body from the inside out by spawning demonic arms from within her.

Aftermath
Susamaru succumbs to the curse and her body is completely crushed by the demonic arms. Tanjiro regroups with everyone in time to view the horrific scene. Yushiro rushes over to cover the demon slayer's mouth so he doesn't inhale Tamayo's spell.

Tamayo studies Susamaru's remains and reveals she is not one of the Twelve Kizuki. All Kizuki have their number engraved on their eyeballs, which Susamaru does not. She is also far too weak, despite being a powerful Demon in her own right.

Yushiro believes their enemies got exactly what they deserved and Tamayo takes a blood sample anyway. Then she leaves to treat Nezuko, who's been both medicated and effected by her Magical Aroma of Daylight.

Tanjiro notices Susamaru's faint voice and is merciful enough to return the temari to her before the sun rises and turns her remains to ashes. Tanjiro realizes that Susamaru was deluded into believing she was a member of the Twelve Kizuki and manipulated to fight for Muzan, only to be mercilessly slaughtered by his curse. This is how the original Demon treats even his own subordinates.