After the same time length reaching Final Selection, Tanjiro, Yuichiro, Nezuko, and Muichiro return to the mountain Urokodaki resides at. The group struggles through the pain all the way back.
Yuichiro: Do you really believe there's a way to turn demons back into humans?
He asked annoyed.
Tanjiro: Why do you ask?
Muichiro: You keep asking the demons before you behead them.
Tanjiro signed looking down at the ground.
Tanjiro: I know they'll never say anything, and I have to kill them, but it's honestly worth asking.
Nezuko: You can be so weird sometimes, but that's why I love you so much Tanjiro.
As soon they all reach the home of Urokodaki they drop to their knees exhausted.
Tanjiro: We actually did it. We came out alive.
Nezuko: Honestly didn't think we would survive all this.
And soon enough Urokodaki comes outside seeing that four of his students returned and hugs them.
Sakonji: I'm relieved that you all came back alive.
He says crying.
Sakonji: The day you all left, I felt a heavy heart attack for each passing day. Thank you for giving my students peace.
(15 days later)
Nezuko: Uh Tanjiro.
Tanjiro: Yes?
Muichiro: There's a man all the way out there.
Tanjiro along with Yuichiro steps outside to see a wanderer with a sunflower-patterned haori and has his head wrapped in a spotted head scarf. His face is concealed by a (wooden festival mask) to conceal his identity. He wears a large, woven hat with hanging floral wind chimes on top of the head scarf.
Tanjiro: Who are you?!
??: Hotaru Haganezuka. I'm a swordsmith who forged the blades for Yuichiro, Muichiro Tokito, Tanjiro, and Nezuko Kamado.
Tanjiro: That's us, please come in.
Muichiro: Do you want some tea?
Hotaru: Nichirin blades are forged from iron sand and the hardest ore. Raw material found in the mountain highest to the sun. The scarlet crimson iron sand and the scarlet crimson ore. They are metals that are fully absorb the sunlight.
Tanjiro: Is he ignoring the fact that he could get his bag covered in mud?
Sakonji: That's just him, he doesn't listen to anyone but his own thoughts.
Tanjiro: Well can you at least stand up please?
Hotaru looks at the new demon slayers revealing a wooden mask with a strange expression. Nezuko hides behind Muichiro as Hotaru observes the children.
Hotaru: Ah. The children of the burning crimson sun.
He says as he stares at Kamado siblings.
Hotaru: This is auspicious for us to meet.
Tanjiro: You must be mistaken. We're Kie and Tanjuro's eldest children.
Hotaru: That's not what I meant boy. Your hair and eyes are red right? If a family with a business of making firewood, then they will have a kind child like you. The point of my meaning is that it's a very lucky thing to be born around a special fire like your family. So, if you were born with a special power, then your sister and your friends could be strong in their own way. That could mean one of these blades could turn red. Right Urokodaki?
Sakonji: Possibly.
Hotaru finally came in to see what color the blades would turn.
Hotaru: Alright. Try and pull the blades out of the scabbard. Nichirin blades are also called the blades that changes color. The blade's color changes based on the owner's individual power.
Tanjiro, Yuichiro, Muichiro, and Nezuko pull their blades out of their scabbards. Tanjiro's blade is surrounded by a fire vortex and when the vortex ends the blade's color shows a bright crimson red with fire symbols all over the blade.
Muichiro's blade was surrounded by a shadow vortex and when the vortex ended it turned purple.
Yuichiro was next and his blade turned into a whitish color.
And finally Nezuko, but hers was different, her blade turned black.
Hotaru evaluates the blade's color.
Hotaru: The boy's blade is red!
Nezuko: But mine is black. Doesn't this feel very ominous?
Sakonji: No. Actually this is the first I've seen a blade turn this shade of black before.
Hotaru: Like I said, I was expecting one of the blades to turn red.
He says satisfied.
??: Caaaawwwww! Yuichiro, Muichiro Tokito, Tanjiro, and Nezuko Kamado. It is time for your first assignment as demon slayers.
Their crow said.
Muichiro: So that's what they meant by the crows can communicate.
He says disturbed.
??: Remember this well! In the town north-west from here, young girls are constantly disappearing!
Sakonji: I believe you four are now ready to look out for yourselves.
The four change into their uniforms Tanjiro comes out first with his uniform on, his checked haori, and his bandage over his forehead removes.
Then Yuichiro comes with his uniform on, his dark, sleeveless yukata with a white mist design.
Then Nezuko comes out in her uniform.
Yuichiro: Umm Nezuko?
Tanjiro: How come your uniform has a small skirt?
Sakonji: I failed to mention this. The tailor for the uniforms has a pervert side. So, he gives the uniforms for femal's skirt that go above their knees.
Nezuko: I actually like it.
Tanjiro felt irritation towards that tailor, but calms himself.
And finally Muichiro comes out with his uniform but it seems his and his haori were too big for him.
Yuichiro: Um Muichiro?
Muichiro: What is it brother?
Tanjiro: Why did you get oversized clothes?
Muichiro: Because I want to.
Yuichiro: How does your mind work?
Nezuko: I think it's quite cute.
She says giggling and blushing at the same time.
Sakonji: Before you all go head off on your journey, there's two things I need to tell you. If you see caster demons, you must be on your guard at all times.
Tanjiro: Caster demon?
Sakonji: They're demons that uses a kind of magic called blood demon art. There will be demons like that in your future missions.
The four nodded understanding the danger they will face.
Sakonji: Finally I say this with every single warning. In this world, there is one demon whose blood flows through his veins, has the ability to turn humans into demons. He was the first man who became a demon over a thousand years. He is the sworn enemy of the demon slayer corps. He must've been the one who sent this "Kurayami" person after your family.
Tanjiro: Does he have a name?
Sakonji: His name is Muzan Kibutsuji.
Nezuko started to feel her heart race under panic hearing that name, she hugged Tanjiro out of fear and cried slowly.
Nezuko: Is he dangerous?
She ask shakily.
Sakonji: Yes. Those who encounter him are never seen again.
Yuichiro: We'll keep that in mind.
Now the four head off on their new adventure as demon slayers with Urokodaki seeing them off.
Sakonji: Take care you four. I will pray for you every night.
The Tokito brothers and Kamado siblings arrive at the town where the disappearance took place.
Nezuko: So, what should we do guys? They won't come out until night.
She said quietly.
Yuichiro: We should gather information of the latest victims. Lets split up and who ever finds a lead will send their crow to the other.
Tanjiro/Nezuko/Muichiro: Got it.
The four split off to find information. Tanjiro passes a young man with dark-brown hair and brown eyes with white pupils. He wears a dull, blue iromuji kimono with a dark-colored obi and light-brown haori. He has a bruise on his face.
Tanjiro then hears the townsfolk talking about him.
??: Kazumi feels devastated. He feels responsible for Satoko's disappearance.
??: It's unsettling that this happens every night.
??: I agree. In the middle of night young girls disappear.
Tanjiro turns back around and catches back up to Kazumi.
Tanjiro: Excuse me Kazumi was it? I would like to know about the girls that vanish in the night. May I?
They head to the spot where Satoko was seen last and surprisngly Muichiro was also there.
Tanjiro: Muichiro you're here too?
Muichiro: Yeah I asked someone about the disappearance and it lead me here.
Kazumi: Ahem.
Tanjiro and Muichiro turned to him.
Kazumi: Anyway this is where Sakoto was when she vanished. But you two probably wouldn't believe me anyway.
Tanjiro: We believe you. I already got her scent. If I can trace her scent, then we might find her kidnapper.
Tanjiro started to sniff close to the ground using Sakoto's scent to track down the demon. Kazumi wonders if he knew what he's doing but begins to lose hope when it turns dark. Suddenly Tanjiro felt the demon's scent and ran as he could, running with Muichiro on the roof landing into an alleyway.
Tanjiro: (Two smells. One is a demon and the other is a young human women. They're right below me. I can't see where they are. So, I'll have to strike where the scent is the strongest!)
He then tells his plan to Muichiro, then he stabs the ground and a black substance emerges from where his sword stabs. A girl emerges from the black water and Tanjiro wastes no time grabbing her. Soon a demon in the form of a pale skinned young man with long blue hair with two long strands of violet on both sides of the face, supported by two golden hair separators. He had claw-like nails and the veins on his forehead are quite prominent, in his case, to the point of replacing his eyebrows. His eyes were red without pupils and with prominent dark eye bags. He had a single horn in the upper center of its forehead and wore a full-length long-sleeved ninja uniform with meshes on its wrists and neck, the mesh of the neck having three small ribbons centered hanging from it rises from its own marsh water.
Tanjiro: Where are all the young women that you kidnapped?!
The swamp demon only grinned in confidence and retreated back to its portal.
Tanjiro: Kazumi, take her and stay close! As long as your both in our range, we can keep her safe!
Then out of nowhere, three swap demons appear around them. One had two horns, one on each side of its forehead. His ninja attire did not have sleeves, instead, it had two small triangular meshes in the armpit area and a large triangular mesh on his chest.
The other had three horns, each in the position in which the other two bodies had their own horns and wore a ninja garment sewn with meshes on both sides of the arms, shoulders, and thorax. Under his coat, he wore a sleeveless bottleneck shirt.
All they could do was jump to avoid getting capture and prepare to attack.
Sun Breathing, 8th Form:
Sunflower Thrust
Tanjiro strikes the portal with a sun like attack from the tip of his sword blasting the swamp demon and his clones away.
Tanjiro: (That was too shallow. It was only powerful to separate them.)
One demon emerges from behind to grab the girl from Kazumi.
Moon Breathing, 10th Form:
Drilling Slashes-Moon through bamboo leaves
Muichiro was able to keep it away by pushing it back.
??: Quit getting in my way you bastard! That women is already 16 years old! If I don't eat her soon, she'll lose her freshness!
??: It's okay my duplicate. In the nights like these, I've devoured many 16 year old girls from this town. The flesh from every single one was delicious. I've already had my fill for tonight. But it's not enough to fill my lust up! I want more!
Kazumi: You monster!
He said shakily.
Kazumi: The girl you kidnapped last night. Please give me back Satoko.
??: Satoko? Who are you talking about?
He opens up his kimono revealing a large number of hairpins.
??: These hairpins are all keep sakes to remind myself of the girls that I ate. If this girl's hairpin is in this collection, then she's already dead.
Kazumi was brought to tears when he recognized Satoko's hairpin in the collection, Tanjiro and Muichiro were enraged to hear the kidnapped girls were all devoured. This allowed one of the clones to attack them, but Tanjiro dodged and sliced his arm and Muichiro protected Kazumi in case any of them got close. One of the demons appeared behind him going for the fatal blow, but suddenly, the two horned close is kicked spinning his head around. They turn to see that the kick was from Nezuko.
Nezuko: Well I see you guys found the demon first. Not to mention you engaged without waiting for me or Yuichiro.
Tanjiro: Sorry. But if we didn't act quickly, he would've eaten another victim.
Nezuko then signed.
Nezuko: Well I'm here now, and it looks like the odds are even.
??: Well, that was a powerful kick. I'll have a splendid time devouring you.
Tanjiro, Nezuko, and Muichiro were prepared to face the three swamp demons, and complete their first mission.
(Notes)
I felt the need to give Tanjiro a bright red Nichirin blade right away. It's not powerful at the moment, but it will be soon.
Nezuko will have enhanced strength that matches a demon.
The next chapter will finish their mission and they will meet a certain man.