'YOU ARE THE ONE GOING TO HELL MUZAN!! I WILL DEFEAT YOU FOR SURE!!!'

'Come and get me if you can, KAMADO TANJIROU!!!'

Tanjirou woke up with a start as he sat uprightly on the bed. He had beads of sweat dripping from his head as he tried to control his breathing. Suddenly, he squinted his eyes noticing the bright light that shone in the room. Something felt different about this place. There was no fragrance of wisteria. There were times when he came back from missions and was severely injured then came to the Butterfly estate for assistance. He would always wake up with a whiff of wisteria in the air.

Tanjirou noticed that he was not injured. His body was in perfect condition. But why was he here then? He wasn't engaged in any recent battle till-

'Muzan!' He stood quickly as all the thoughts rushed through his head.

He remembered. He was rushing to the estate along with Tomioka. Just Before they got there, the Ubuyashiki mansion exploded. They rushed quickly only to see the demon himself with Tamayo stuck to him. Each of them unleashed their breathing forms till they started falling into what he assumed was a trap set for him.

That's right! The others were fighting with their lives on the line and he was here slumbering. But all this didn't feel right at all. He shook his head to clear any doubts. He had to get to the others and help them as soon as possible. He had to go to Tomioka's aid.

At that moment, the door slid open revealing a tall man standing in the doorway. He wore a tired and grim expression on his face. His unruly long hair reached his shoulders and his black piercing eyes with a binding cloth wrapped around his neck. The man kept his eyes on the awoken slayers before glancing across the room and raising his eyebrows.

'How was a bunch of teenagers able to get past security without any signal going off?' Aizawa contemplated. 'As if my day couldn't get more annoying.'

Tanjirou glanced at the man with confused eyes. Something about him felt unsettling. He had a good reason to be though. Nothing around him felt right. He was off facing Muzan a second ago. Now he was here! Just that he didn't know exactly where.

He didn't know that he was shaking till he felt a hand placed on his shoulder.

"Kid, it's okay now. You are safe." Aizawa calmly stated. He hoped that worked because he tried his best to not let his mood make him uncomfortable.

Tanjirou managed to calm down a little. Yet, he felt odd. Everything here was odd. He was startled when he turned seeing his two friends lying on separate beds next to him.

'They are also here. And it seems like they are unconscious too. What is going on?' He noticed that Inosuke had his mask removed. Slowly, he turned back to the pro-hero.

'This man's different. He has a strange aura hovering around him.'. He thought. 'But_'. However, The burgundy-haired slayer froze.

'To think a bunch of kids are moving around with swords? Real swords?!' The pro hero thought as he recollected earlier when Kendo and Monoma told him they had swords. They showed it to him of course. He and Vlad King confiscated them for now. His thoughts came to a halt as something suddenly popped from his binding cloth.

"Thanks for the ride, Aizawa," Nezu said with a cup of tea in hand. Aizawa only stared blankly at the... bear...mouse(Author-san has no idea) wondering how he got there in the first place. Sure, he called the principal but didn't expect to appear from his scarf-like material.

That was when it clicked in Tanjirou. A mouse can't talk unless...

'It's a demon! This should be a blood demon art or an illusion or dream state like with the battle with lower moon one on the Mugen train!' His fists tightened after the last assumption he had.

Aizawa studied the boy's disposition before his eyes met the burgundy-haired slayer. His eyes were full of determination and coldness. The softness was gone in an instant. The man widened his eyes in realization, quickly about to use his cloth.

Unfortunately, he was cast aside by Inosuke who roughly shoved him to the wall. Before Tanjirou could react, he was tugged by Zenitsu running past the door into the hallway.

"Took you long enough, Senpachiro!" Inosuke yelled at Tanjirou before putting on his boar head mask.

"Inosuke! Zenitsu! How did you_?" Tanjirou looked at the duo wondering how they figured it out while they were sleeping.

"We were pretending after we woke up and saw one of the demons. It would be troublesome carrying you while running. So we waited for the right time." Zenitsu explained. He was also terrified of the fact that he did not know where he was.

"Monitsu wanted to stop me from beheading one of them. He kept watching us like a creep." Inosuke began fuming till Zenitsu screamed.

"YOU IDIOT! HOW DO YOU EXPECT US TO SLAY THEM WITHOUT OUR SWORDS?!"

"WHAT DID YOU CALL ME CHUPITSU?" Inosuke shouts with the same tone laced in his voice.

'That's right! Our swords... We didn't see them.' Tanjirou sniffed the air. He smelt rage. Surely, it wasn't the bickering slayers in front of him. Zenitsu shuddered slightly looking back.

"EEEEEK! RUN YOU GUYS, THE DEMON LOOKS PISSED!" Tanjirou looked back. To say Aizawa was mad was an understatement. His eyes glowed red and his hair stood hovering in the air. Tanjirou couldn't believe he almost trusted this guy. He was certain that he was a demon now.

The three slayers ran using their total concentration constant giving them the upper hand. Aizawa was stunned by the speed, nonetheless, he hurried hoping to stop them before anything got out of hand.

They were barely within his sight, if not that there were any corners, he would have lost them.

Tanjirou continued running before his eyes shone in recognition. "Genya!" The black Mohawk slayer perked up from his dazed state wondering who called his name and why the voice sounded familiar.

"Look, it's Kenya!" Inosuke excitedly stated. An irk mark formed on Genya's head immediately after he was relieved seeing his comrades. " You are hopeless not to be able to pronounce my name"

'Huh?'

'Meh! Close enough.' The others shrugged it off. Soon they passed a group of students who were coming out of their changing rooms in hero outfits. Tanjiro and Genya, avoided them while running while Zenitsu and Inosuke jumped over them before continuing.

"What just happened?" Awase asked breaking the awkward silence.

'Why are they up and running? They were pretty fast too.' Monoma thought. He didn't expect to see those strangers dashing across the hallway. His thoughts came to an end when he saw a frowning Aizawa going after them. 'What is going on?'

Genya clicked his tongue in annoyance. He ran into the same group of 'demons' but they looked older. Luckily, he was able to evade them. Seriously, where the hell are they? This almost felt real.

'Tch! Pesky demons!'

Out of nowhere, a door flung open revealing a girl with a butterfly pin, her hair packed into a side ponytail, and wearing a demon slayer uniform. Her face was etched with anger while glaring at one of the second years trying to flirt with her.

"Kanao!" Tanjirou shouts relieved to find another friend of his. She didn't notice them until after kicking the second-year boy aside.

Her expression was still filled with fury but flickered off at the sight of the boys. "So you also met the demons too," Genya stated. Kanao nodded in agreement.

"It's a coincidence I guess. For all of us to meet each other." Genya continued with a relieved expression. Tanjirou nodded in agreement. At least they had each other, which was good.

"I can hear him. He's getting closer." Zenitsu began slightly panicking. The other nodded continuing their dash. Jumping down the stairs and ignoring any 'demon' they found in sight. Kanao couldn't find her sword when she woke up and Genya couldn't find his gun either. He also had a hard time keeping up with the others since he couldn't use breaths.

It came off hopeless as they continued running turning to every corner they could find. Hoping that it would lead them outside at the very least. This place was big for a bunch of demons. Maybe it was like a demon organization? They had to get out of there as soon as possible and rejoin the others in the battle.

Hagakure stood there trying to get rid of the thought of seeing a half-naked boar running in the school with the rest of the slayers from a window reflection. The fact that she was the only one who noticed was slightly amusing in a way. They had finished their exercise a few minutes ago. She zoned out by the time Midnight was announcing the result.

"Hagakure, are you listening?" Mina asked the invisible girl in her sportswear.

"Uh... Yeah, sorry, I zoned out there." She said waving it off but Mina had no idea. She looked back to Midnight who was on the phone with someone till she ended the call. Her face shone with passion and perplexity.

"That's the end of class students. You are free to head back to change." She said dismissing the class. Everyone nodded before going back into groups while chatting with each other.

"Am I seeing things?" She questioned herself before shrugging it off and rejoining to the others.

Aizawa noted them from where he was. It seemed like they also had newcomers as he fixated his gaze on Genya and Kanao. The slayers descended swiftly down the stairs parkouring without a sign of fatigue. The pro-hero simply used his cloth-like scarf to help himself slide down enough to catch up on them.

"Damn, blood demon art!" Zenitsu sighed in frustration eyeing the man. He had enough of these demons. They were a pain to all of them. After turning again, their eyes lit with hope. Seeing a door wide open, the sun rays reaching the doorway.

Just as Tanjirou was about to reach the door, a wall of cement blocked their way startling them. They faced the opposite direction to see all two other 'demons'. They frowned knowing that they lost their chance thanks to his blood demon art.

"Are these the teenagers you talked about on the phone?" Cemontoss looked at Eraser head.

"Yeah, They may be teenagers but are skilled." He faced the slayers but with his hair down and his eyes reverted to normal." Look, we are not the bad guys alright. We would just take you in for questioning. How you got in here without the security alarm going off for example?" Genya didn't trust him one bit. It kind of reminded him of when he, Tanjirou, and Nezuko were battling Upper Moon Four.

"Don't underestimate the lord of the mountains, I'm gonna murder every one of you, demons!! " Inosuke screeched. The pro heroes took a mental note of what he said. Aizawa narrowed his eyes at the slayer. 'Murder every one of us demons?'

"Seriously, I need you all to calm down. We can sort this out." Aizawa spoke tiresomely. ' I might need a break for a few days after this.'

"HOW THE HELL ARE WE SUPPOSED TO CALM DOWN WHEN WE ARE SURROUNDED BY DEMONS, HUH?!" Zenitsu screeched. Aizawa deadpanned at his ridiculous yet humorous expression.' This kid has a strong pair of lungs...'. The slayers didn't lower their guard at all and didn't relax at his message.

" Beast breathing, Eighth fang, Explosive rush." He stated rushing towards Cementoss. The pro hero didn't react in time and was tackled aside.

Kanao leaped towards Eraserhead about to land a kick on him. He quickly used his binding cloth against her leg tossing her away but she regained her balance and leapt towards him again.

A moment after she leaped, He came face to face with the burgundy-haired teen who delivered a headbutt to him. 'What kind of forehead does this kid have?' Aizawa contemplated trying to recover quickly while staggering back. Unfortunately, Kanao landed a solid kick on his back. He landed roughly with his chest on the ground.

Taking this opportunity, Genya and Zenitsu attempted to use his cloth against him. Aizawa quickly recovered using his quirk to make the scarf float and pulled the cloth causing both of them to lose their footing.

Soon, Present Mic arrived at the scene.

"STOP MESSING AROUND KIDS!!" Present Mic yelled much to the dissatisfaction of Zenitsu who had his ears throbbing. Inosuke jumped high but flinched at the loudness. He hadn't expected that at all.

Something was not right. Tanjirou sniffed the air again. His mind was slowly feeling hazy. Kanao wanted to knock Aizawa out but he grabbed her leg, tossing her to Tanjirou. He noted the pink gas being secreted.

'Some kind of blood demon art?' Tanjirou fell to the ground with Kanao on him. Just as soon as he did, Aizawa sighed.

"You are late Nemuri."

"Is that your way of saying thanks, Shouta?" Midnight smirked playfully. Very soon, she had a serious look.

"So care to explain?" Looking around, she saw Present Mic aiding Cementoss on his feet and unconscious teenagers.

"Looks like you've wrapped things up here." Nezu appeared from his scarf.

'So he was watching.' Aizawa frowned.

"I'll reach Detective Tsukauchi about this case. In the meantime..." Nezu began worriedly as he glanced at Eraser. "You should go see Recovery Girl."

Aizawa couldn't agree more. His forehead was bleeding from the recent headbutt that Tanjirou administered to him.

Taisho secrets

* Aizawa concluded that he had found new problem children specifically Tanjirou and Inosuke.

* Monoma couldn't stop staring at Inosuke because he had a beautiful face.

#Preview

" I AM HASHIBIRA INOSUKE! LORD OF THE MOUNTAINS!! GOT THAT MINIONS! WE WILL DEFEAT THOSE DAMN DEMONS!" Inosuke stated confidently.

"LIKE HELL, I'D CALL YOU THAT!" Genya roared.

"You wanna fight me?" Inosuke challenged. The other three stared blankly at the two quarreling.

"I can't believe we got caught by demons. This isn't how my life was supposed to end!" Zenitsu cried with tears streaming down his cheeks. Kanao and Tanjrou blinked at the three making a nuisance.

"We have to escape. No matter what, we have to join the others to fight against Muzan. " The others stopped and looked at Tanjirou. "Let's fight together."

"Next, Chapter 5: Meeting the pro heroes, interrogation,"

To be continued...