Inosuke Hashibira is a boy like Tanjiro, wearing a boarhead costume and wielding two swords, he stole some swords from the demon slayers passing by and Inosuke designed the swords by damaging the blades on it looking like a more intimidating version.

[Thudding sounds]

"I sense a demon!" The excited Inosuke while dashing to the shifting rooms, he dash around the hallway as he hears the demon's footstep at the distance.

At the corner of the hallway, a giant horned demon saw the running Inosuke dashing towards him. The demon smiles in creepy expression while leaning at the wall.

"You really look for me? It's been a few days since you got lost here you annoying boar!" The horned demon in deep and creepy tone

The demon grins, the demon walks away to the different path around the room to avoid Inosuke.

"Finally I saw you! Gruuuwaaaah!" Inosuke yells while dashing at the demon.

Inosuke leaps towards the horned demon and attempts to lunge his blades but the demon shuts the door.

"Damn it!" Inosuke destroys the door room by kicking it. He enters inside and saw the demon is gone now.

To his surprise, the demon appears behind Inosuke attempting to catch him offguard.

"Kahahahaha~!" The horned demon laughs while trying to catch Inosuke with his big arms.

But Inosuke evaded and manage to cut the horned demon's two arms.

[Slashing sounds from the flesh]

"W-what!?" The demon exclaimed with surprised and fearful expression

Inosuke laughs deeply as he says "don't get cocky with your big body! I can cut it like a butter!"

Inosuke bended his knees to pose his attacks while snorting

"Beast Breathing....Third Fang..."

Inosuke swings his two blades towards the powerless demon's neck

"...Devour!" Inosuke shouts while beheading the demon. His two blades manage to cut the demon's neck.

[Sizzling and burning sounds]

The demon dies as it turn into ashes

Inosuke pant heavily as he recover his breath.

"Damnit, it's been 3 days for looking for that damn big demon....and finally I manage to kill it..." Inosuke then walks off as the Tsuzumi sound continues

[Tsuzumi sound noises, Mansion rotating noises]

Inosuke suddenly trip over and fell to another room after the mansion shifts.

"Damn this mansion!!!" Inosuke in annoyed tone.

This time he meet Saitama and Teruko at the same room.

"You again!?" Saitama raises his eyebrow while holding Teruko in his arms. He was interested of Inosuke's appearance as well as his costume and his origin.

"Huh!?" Inosuke stands up and put up a battle stance, holding his two swords while saying "are you a demon!? You don't have hair! Now answer me!"

Saitama was offended by Inosuke's remarks as he says in annoyed tone "oi, don't insult me like that, I am bald and I am a human! Can't you even tell?"

Teruko clings around Saitama while whispering "that boarhead is scary...."

Inosuke snorts as he grip his two swords, he stare at them while saying "oh well, you got some hostage, I won't allow you to hurt her!!"

"W-what!?" Saitama was puzzled by Inosuke's perspective.

Suddenly Inosuke dashes towards Saitama to attack with his two weapons while saying "gruuwaahh, show me what you got--"

Inosuke's attack were interrupted when he saw Saitama moves so fast as if blinking infront of him.

Saitama knocks off Inosuke with a chop in his collarbone, putting Inosuke to sleep.

Saitama just realize he was still holding Teruko in his arms, Teruko was dizzy after Saitama's movement.

"Oh I'm sorry I didn't mean to make you feel dizzy-" in regretful tone.

Teruko cover her mouth with her right hand and suddenly vomited at the corner "bleeh...."

After that...

Teruko pouted heavily and crosses her arms, she looks away while saying "don't do that again! It makes my brain turn upside down!"

Saitama whined as he sees the cute pout of Teruko, he comforts her by giving her a headpat "I'm sorry, can you forgive me please??" In begging tone while acting like a brother figure.

Teruko smiles as she says "okay! Apologies accepted!" She then hugged Saitama afterwards while humming happily.

"Awww how cute~" Saitama hugs her back and then breaks the hug afterwards.

Saitama still carried Teruko in his left arm, his right arm dragging the unconscious Inosuke. Still finding Tanjiro and others.

[Tsuzumi noises]

The mansion suddenly changes their direction, Saitama is getting impatient as he just kicks each door he sees since his hands are busy holding someone.

"Damn this place, it's just like a maze...but more annoying and a waste of time..." Saitama mutters

....

....

Meanwhile Tanjiro.

Tanjiro was walking at the hallway, going inside the room and checks on each door room, he also see some rotten corpses as he pray on them before walking off.

Luckily, he manage to open the door where he can see a young boy with a wounded leg.

"Are you Kiyoshi?" Tanjiro in curious tone.

The wounded boy nodded while sobbing emotionally "I'm Kiyoshi, are you here to save me?"

Tanjiro immediately walk towards him, he kneel down and helps him by bandaging Kiyoshi's right leg, Tanjiro put some healing cream to his wound while saying "this cream helps you to ease your pain, Yushiro gave this to me..."

Tanjiro untied some cloth from his arms before covering the wounded leg of Kiyoshi. "There you go, feeling better now?" Tanjiro asked while smiling

Kiyoshi nodded while smiling in grateful manner "thank you very much!"

[Door creaks]

Tanjiro gets startled as he stand up and put up a battle stance, holding his sword, he was unsure of someone opening the room if it is a demon or a human. Tanjiro is observing the door to get opened.

"Is it a demon? There's no scent but I can't be sure..." In Tanjiro's thoughts

As the door is opened, Saitama and Teruko enters the room.

Tanjiro sighed in relief seeing Saitama "geez mister Saitama, you almost gave me a heart attack..." He chuckles.

"Tanjiro don't make me feel worried again...or else that old man Sakonji will haunt me everyday." Saitama sighed as he gently put Teruko down.

Teruko saw her elder brother Kiyoshi who is sitting with bandaged leg.

"B-big brother...." Teruko's eyes become watery, she run over to Kiyoshi and hugged him tightly "big brother! I was scared of losing you!"

Kiyoshi hugged Teruko back and cries while saying "I'm alright now, don't be sad...let's go home together..."

Teruko cries emotionally as she says "brother Shoichi was separated from us, but I'm sure he will be alright!"

Kiyoshi comforts Teruko by gently giving her a back rub, he then says "I know he will be alright..."

Tanjiro felt a heartwarming scene of the siblings reuniting again, Tanjiro felt a bit sad as he can remember his younger siblings, the past memory that can't be restored in a present time.

But still, Tanjiro is grateful as he has still Nezuko in his side.

Saitama smiles in proud look as he says "good job kiddo, I know you would make it!" He pat Tanjiro's head as he give him a commending thumbs up.

Tanjiro respond with a happy smile and noticed Saitama is holding someone "who's that?"

Saitama looks at the unconscious Inosuke that he hold from his right hand and answers Tanjiro in curious tone

"I found this guy while exploring the doors, he tries to attack us because he mistakes me as an enemy, but he is not a demon.." Saitama in less caring tone.

[Loud Tsuzumi Noises]

The four people at the same room were startled.

Saitama was a bit surprised of the loudness from the Tsuzumi noises.

But..

[Mansion rotating noises]

The room suddenly twirled making the four people loss balance.

"M-Mister Saitama!" Tanjiro tried to grab Saitama's hand but fails.

"Tanjiro, don't mind me! Take the kids away and find the exit now!" Saitama said while holding the unconscious Inosuke.

Saitama was pushed back from the shifting area, separating him from Tanjiro, Teruko and Kiyoshi.

"Damn it...if only I can blow this entire mansion with one punch, but with people around, I hate to admit I can't do it to avoid casualties.." Saitama mutters while annoyed.

He lift the unconscious Inosuke like a sandbag and kicks each door room he sees, trying to find Tanjiro and others again.

...

...

Meanwhile....

[Door creaks]

Tanjiro's eyes goes wide, he sees a demon opening the door. He gently pull Teruko away protecting her.

"This scent....is more powerful than what I encountered than most demons I killed...!" His sweat drops over his cheek while feeling terrified.

The scared Teruko walks towards Kiyoshi while hugging each other, Tanjiro protects them while on battle stance.

"Kiyoshi! Please protect Teruko, I will try to defeat this demon at all cost!" Tanjiro while gritting his teeth and feeling extremely nervous.

Kiyoshi was shivering in fear, his eyes and lips jerk as he is still brave to protect his younger sister from the demon. He nodded as he answers "I-I will!"

"How dare you enter my mansion, I am Kyogai and the three of you will suffer my wrath! Be prepared!!" Says the angry Tsuzumi Demon.

Tanjiro is feeling scared and nervous of confronting this demon while also protecting Teruko and Kiyoshi behind, he is not sure if he will win or not, but the chances of this demon hurting the civilians first is very high.

TO BE CONTINUED