As Saitama stands while observing the surrounding with Tanjiro behind, the black portal appears below Tanjiro and there were 6 hands trying to grabbed the young demon slayer

Saitama shouts,

"Tanjiro! Below your feet!"

Tanjiro gasped and jumps up while taking a deep breath,

"Total concentration, water breathing..."

The hands of the demons is slowly grabbing Tanjiro's kimono but Tanjiro performed,

"Eight form...Waterfall Basin!"

Tanjiro slashes the hands of the demons, the limbs are sent flying.

"Too shallow!" Tanjiro thinks.

The demons regenerated their arms and the black water portal vanishes again.

Saitama looks at the surrounding while clenching his fists.

Tanjiro pants as he protects Kazumi around.

And the 3 demons shows up.

Their teeth gnashing and produce a wierd sound as if they are angry.

Saitama goes serious as he observes them

The demon with one horn says,

"There is only one demon slayer here and the rest are humans...but why did I sense a demon at the slayer's box??!"

The demon with two horns speaks,

"Why are you both interrupting us!"

The demon with three horns says,

"Grrr! Grrr! Kill them boys!"

They gnash their teeth producing grinding sounds. It makes Saitama feel discomfort from hearing it.

They went inside the black water portal and vanishes from their sight.

A portal appears below Saitama, Saitama was surprised as the demons dragged him below.

Saitama then thinks,

"If I give them a strong punch, I might accidentally destroy this entire town..."

Saitama lunges his fist to the demon with enough power to splatter them but his punch produce a tremor.

"Oops.." Saitama jumps up back to the ground as he wipe the dust, his pants got wet from the demon's swamp realm.

Tanjiro shouts with concern,

"Mister Saitama are you okay?"

"Yeah I'm fine, don't mind me..." Saitama says in casual tone.

Kazumi was surprised of Saitama's punch as he drop down from shock, he thinks,

"T-this guy...he punch the demon and it produce a small quake?"

A small black water portal appears behind Kazumi.

Saitama in quick reaction moves in the blink of an eye, he tried to grab the demon but the demon's arm was torn as it escapes back inside the portal.

"Oh..." Saitama's exclaimed as he throw the demon's arm away feeling disgust.

The portal appears again at beside Kazumi and tried to capture the girl.

But..

Nezuko went outside the box and kicks the demon with two horns away.

"Guahh!!!" The demon was sent flying crashing in the wall from Nezuko's kick

Tanjiro gasped and then smiles from Nezuko, he told Nezuko,

"Nezuko please assist Saitama and protect Kazumi.."

Nezuko stares cutely at his old brother and nods.

Saitama smiles with a pinkish cheek as he approach Nezuko and patted her head.

"Nezuko~ are you awake now?" Saitama grins as he was charmed by her cuteness again.

Nezuko reacts back with a pat in Saitama's head, and Saitama doesn't mind at all.

Nezuko also stares at Kazumi who is holding the unconscious girl. She walk slowly and touches them

As Tanjiro sees Nezuko touching Kazumi and the unconscious girl, he remembers what Urokodaki said.

Back when he was talking to Urokodaki, his master told him about the hint of Nezuko's ability to resist the temptation to attack humans.

"Nezuko loves your family..."

The voice of his master that reminds him of his past.

Tanjiro smiles as he mumbles

"Thank you Nezuko...Thank you master Urokodaki.."

But.

A black water portal appears and the 2 demons manage to grabbed Tanjiro's leg and dragged him inside the swamp realm.

Saitama noticed Tanjiro getting dragged and tries to save him,

"Tanjiro!" Saitama tried his best to grab Tanjiro but fail to save him.

Before Tanjiro can be dragged inside, he take a deep breath when he knew the realm is full of water without air.

Tanjiro went inside the swamp realm,

And floats while he can see some clothes of the young girls floating around.

Tanjiro gets angry as he knew these demons are killing young women.

The 2 demons swam and sprint towards the serious Tanjiro.

Tanjiro uses his air stored in his mouth and performs

"Water breathing, second form....waterwheel!"

Tanjiro slashed the limbs of the 2 demons floating in the water, they move back and move away, they regenerated their lost limbs and went back to their offense,

The 2 demons at different spot is now sprinting again towards Tanjiro.

Tanjiro while floating tighten his grip in his katana as he goes defensive stance.

The 2 demons grinded their teeth while moving, they produce an ink-like from the squid as they boost their movement in swimming.

"They can move like that down here!?" Tanjiro thinks while cautious.

They move in circular movement and now goes to lunge towards Tanjiro.

"Die you brat!!" The demons shouted

Tanjiro can see the thread forming up in the demons' neck as they approach Tanjiro.

"An opening!" Tanjiro while preparing to strike.

Tanjiro uses his stored air in his mouth as he swirl his blade and performs...

"Total concentration, sixth form...

Tanjiro swirls his blade weapon as it produce a whirlpool, pulling the 2 demons towards him and slashing their limbs until their necks are finally cut.

The head of the 2 demons float above as it slowly burns to death.

After finishing off the 2 demons, Tanjiro stare at the torn clothes of the Swamp Demons' victims. Then he notice a familiar cloth from Kazumi's lover.

Tanjiro grabbed the black torn cloth from Kazumi's lover and swam back up in the ground.

...

Meanwhile,

Saitama manage to beat the remaining demon with two horns, the body is crippled as it sits down panting.

Nezuko is still protecting Kazumi around while Saitama deals with the last demon.

Saitama says,

"Why are you killing young women? Why are demons like you doing that thing..?"

The demon with two horns regenerated as it answers Saitama angrily,

"Young women are delicious meat for us! We will kidnap them and eat them while their body are still young! If they reach at the old age, their body are not delicious anymore!"

Hearing the ridiculous reason of the demon, Saitama with a detailed face clenches his fist preparing to give the demon a good punch.

The serious Saitama says,

"The young women you killed has a bright future, you demons are just nuisance in the society.."

Angered by Saitama's comment, the demon grinds its teeth and lunges towards Saitama while saying,

"What do you know about us!? Just die!!"

Saitama evades and chop the demon's shoulder, sending it sinking in the ground from impact.

Kazumi gasped as he was impressed of Saitama's reaction.

Nezuko in a chibbi appearance tilt her head a little

The demon shiver in pain after inflicting pain from Saitama, it tried to stand up and tries to escape using its water portal, but Tanjiro appears on it and headbutts the demon out from his way

Saitama sighed in relief after knowing Tanjiro was safe after getting dragged in the swamp realm.

The demon was sent flying crashing in the wall, cornered by Saitama and Tanjiro.

Tanjiro speaks in a serious tone, he say,

"Do you know anything about Muzan Kibutsuji...?"

Tanjiro pointed his blade on the demon's face

Hearing the word of Muzan Kibutsuji, the demon shiver in fear and its face turns extremely pale.

The demon speak in a scared stuttering tone,

"I-I can't..I can't tell you that..."

Tanjiro slashes the demon's mouth and warns him,

"Tell me everything about the demon king!!!"

Saitama crosses arm while watching them, his face turns casual after the mission is a success

Tanjiro glares at the two horned demon and thinks,

"Is this demon getting threatened by the demon king about not telling everything about him...so that explains why it is scared to tell about Muzan Kibutsuji.."

As the demon shivers in fear, a imprinted warning shows up before his eyes, a figure of Muzan Kibutsuji gesturing the demon not to reveal his identity.

The two horned demon snarls and leaps towards Tanjiro.

Tanjiro sighed deeply as he reacts and decapitated the demon off to death. The two horned demon burns until it vanishes.

Tanjiro clenches his fist as he look down, he thinks,

"Muzan Kibutsuji, you bastard...I'm gonna find you and kill you by myself...."

After seeing Tanjiro's anger and sadness, Saitama approached him and puts his hand around Tanjiro's shoulder, he then says,

"Tanjiro...don't worry..." Saitama speaks in reassuring tone..

Tanjiro sigh as he smiles and says while looking down,

"I'll train harder and kill Muzan Kibutsuji..."

After the sunrises, Tanjiro approached Kazumi.

Kazumi puts the unconscious girl down, bends down and cries out in agony.

Tanjiro kneel down to his height as he comfort him.

"Life must go on..."

He gave Kazumi the torn cloth of Satoko, and after seeing the cloth, Kazumi cried pathetically as he can't forgive himself for losing his lover.

"S-Satoko..." Kazumi sniffles and cries out loud.

Kazumi hugs the torn cloth from Satoko and cries emotionally.

"You don't know how it feels to lose someone! What do you know about us...!"

Tanjiro hold his hand, and Tanjiro says,

"Everyone has the same fate as you, not only you experience it.."

Tanjiro stood up feeling sadness as he turn back and walks away,

The smiling Saitama gestures Nezuko to crawl back to the box before Saitama gave the box back to Tanjiro.

As Tanjiro and Saitama walks away, Kazumi realizes something.

He thinks,

"The young slayer has a rough hand and scars, describing how he trained hard to protect us....so that means.."

Kazumi realizes that Tanjiro's fate is worse than him.

Kazumi stood up and shouts,

"I'm sorry! I'm sorry for judging you...."

Tanjiro while waking waves his goodbye and says,

"I'll leave the unconscious girl to you mister Kazumi, please return her to her parents..."

As they walk away,

Saitama looks at him and says,

"Are you okay kiddo?"

"Yeah...I'm fine" Tanjiro smiles, his smile shines bright like a sun.

Saitama also smiles warmly

"I see..."

Saitama walks beside Tanjiro, he has dust in his clothes and the sun is shining bright.

Saitama put his hands on his pocket as he told Tanjiro,

"Let's eat some soba noodles..."

"Yeah sure--"

But the chatter was interrupted when the Kasugai Crow flew and rest at Tanjiro's shoulder shouting,

"Next destination! Asakusa Tokyo, rumor says there are demons lurking there."

Tanjiro makes a tired look as he says,

"Do we have to go there right away?"

The Kasugai Crow answers while gesturing Tanjiro with its wings,

"Yes right away."

"Wait wait wait I just finished my first mission can you let me rest"

"Noo!"

The Kasugai Crow peck Tanjiro repeatedly.

And the annoyed Saitama says,

"Hey talking crow! Don't order us!"

The Kasugai Crow became silent until it flew and rest in Saitama's shoulder, staring quietly.

Tanjiro tilt his head in confusion as he was like,

"U-uhm what is it Kasugai Crow?"

Saitama was baffled when the crow stare at him silently, but then it speaks,

"Kraw! Kraw! Your bald head is very shiny! kraw!"

The Kasugai Crow peck Saitama's bald head before it flies away very fast.

Saitama smiles angrily after getting fooled by the Kasugai Crow's deceiving action.

"You little pesky bird!!!"

The irritated Saitama grab some stone and throws it at the Kasugai Crow.

"Ahh! Mister Saitama calm down!"

Tanjiro tries to calm the irritated Saitama.

Saitama calms down after Tanjiro brought him some dumplings.

And both continue their journey by heading towards the Asakusa Tokyo.

TO BE CONTINUED