"Hey... hey hey hey... th-this... this this this!!!"
"What kind of creature is that!!!"
Inside Omiya Station in Saitama Prefecture, Asuka and his group, travel-worn after days on the road, finally stood before their mission target.
Before them loomed a pitch-black steel behemoth, forged entirely of iron. On the front of the locomotive were embedded massive characters: "Mugen."
Inosuke trembled with excitement at the sight of the Mugen Train, unable to form proper words.
He pointed wildly at its massive body. "This is it... the Lord of the Land! The one that rules this territory!"
"Huh? What are you talking about? It's a train. A train is—"
"No mistake about it... this terrifying aura... Stay sharp! It looks like it's asleep! We can't let our guard down!"
"I'm telling you, it's not—"
Zenitsu, wearing a pained expression, was still trying to explain the concept of a steam locomotive when Inosuke had already gripped his Nichirin Blade at his waist, ready to challenge the steel monster to battle.
"Beast Breathing, Third—"
"Wait! Inosuke!" Tanjiro stopped him. "Don't act recklessly. It might be the guardian deity of this land!"
"No... what are you two even doing..." Zenitsu stared at them speechlessly, stunned at how out of touch they were. "It's a train! A train, okay? A means of transportation! Like an ox cart or horse carriage! You two country bumpkins!"
He turned to Asuka for support, only to find him deep in thought as well.
"So this is a train... how does it move? There's no animal pulling it..."
We're doomed... this mission is doomed... Zenitsu thought from the bottom of his heart.
Before Inosuke could cause an even greater disturbance, Asuka finally acted like a captain.
"Forget that for now. Let's board."
He jerked his chin toward the railway police on the distant platform, rifles slung over their shoulders. "They might not be able to catch demons, but they can certainly arrest us for carrying illegal blades. Don't cause trouble."
With that, he carefully stepped onto the train and began searching for their seats.
"Asuka-san, that's first class! Ours are over here!" Zenitsu quickly sheathed his Nichirin Blade and hurried after him, guiding the train-inexperienced trio.
The sun gradually dipped below the horizon as the train began to move.
The troubled service originated in Saitama Prefecture and was bound for Niigata—a special nighttime Joetsu Line express.
The route passed through complex terrain, cutting through mountains and forest tunnels. Under layers of drifting mist, the journey took on an even more ominous hue.
There were even rumors that the missing passengers were victims of mountain gods angered by the railway department's excavation of rock and carving of tunnels to lay the tracks.
"Let's go."
Once the passengers had settled, Asuka began moving. "First, find the Flame Hashira."
Strangely enough, Asuka had already released his spiritual pressure before boarding.
This train was thick with demonic aura—yet there was no discernible source.
With every step, Asuka felt as if he were walking atop a demon's body. The sensation made him deeply uncomfortable.
Was it hiding somewhere within the train? Or... could it be an Upper Rank? Residual demonic aura left behind by overwhelming strength? Why was it so strange?
They needed to find the Flame Hashira immediately and identify the problem here as soon as possible.
"Hey! Bird Eight-Lang! Let's race!" Inosuke excitedly pounded on the carriage walls with dull thuds, drawing glances from nearby passengers. "Let's jump out and race the Lord of the Land! It's huge! So awesome!"
"Inosuke, keep it down!" Zenitsu hurriedly grabbed him, nervously glancing around. "We can't cause a scene!"
The four moved through the narrow carriage aisle in search of the golden-haired figure.
Tanjiro's expression, however, remained slightly strange.
He kept sensing a faint, drowsy scent lingering in the air.
"Stay alert. There's a demon on this train," Asuka quietly warned, noticing Tanjiro's face.
Tanjiro's expression changed. He said nothing, only tightening his grip on his Nichirin Blade while carefully steadying the wooden box on his back.
Inside it slept his most precious sister—the demon girl Nezuko.
Finally, after passing several carriages, they arrived at the more spacious and brightly lit first-class section.
The seats were more comfortable here, and there were fewer passengers.
But almost the moment they stepped inside, a voice—blazing like roaring flames and brimming with power—instantly seized everyone's attention.
"Delicious!!"
Near the seats closer to the locomotive sat an extremely eye-catching man.
He had brilliant flame-like golden hair, with bright red-gold tips. Parts of his hair stood upward like burning fire.
Beneath his thick sword-like brows were sharp golden-red eyes, as if containing an undying fighting spirit.
"Mm! Tasty! Truly delicious!"
At that moment, he was devouring the contents of a massive bento box with astonishing momentum, both hands holding it as he ate like a whirlwind.
A closer look revealed a towering stack of empty lunch boxes piled beside him.
His booming, energetic voice echoed throughout the carriage, clearly reaching Asuka and the others even from a distance.
This man was one of the Nine Hashira—the Flame Hashira, Rengoku Kyojuro.
Tanjiro, Zenitsu, and Inosuke were momentarily speechless, overwhelmed by the exaggerated eating style and the powerful presence radiating from him.
"So that's the Flame Hashira... isn't he just a regular glutton..." Zenitsu whispered uncertainly to Asuka.
Asuka didn't answer. He simply led the three closer and calmly greeted him.
"Rengoku-san, long time no see."
"Oh! Asuka-boy! Delicious!"
His voice rang out like a bell, brimming with unrestrained enthusiasm as he continued eating heartily.
"What brings you here? On assignment? Mm! Full of spirit!"
"Yes." Asuka gestured for Tanjiro and the others to sit while he took the seat opposite Rengoku. "I've come to support the Mugen Train mission. They're my team members."
"I see! Excellent arrangement!"
Asuka scanned the other passengers in the carriage, confirming no one was eavesdropping, then spoke seriously.
"Rengoku-san, have you noticed? There's a demon on this train."
"Mm! Indeed! A powerful one! No telling when it will appear!"
"Yes. The demonic aura saturates the entire train. Could it be an Upper Rank?"
Rengoku Kyojuro crossed his arms. His expression grew serious, though his hearty Flame Hashira smile remained.
"Upper Rank? Hard to say! I arrived a day earlier than you, and I still haven't located the demon aboard this train!"
"Upper Rank? Finally, someone worth fighting!" Inosuke growled excitedly, fingers rubbing against the hilt of his Nichirin Blade.
Zenitsu looked ready to faint. "Ahhh! Upper Rank?! The whole train is filled with demonic aura?! Is it too late to jump off now?! Help me—!"
Asuka raised a hand, stopping their noise.
"It's not confirmed. We can only judge that the demon here is far from ordinary. Proceed carefully."
"Mm! A very calm assessment! As expected of you, Asuka! You already possess the bearing of a Hashira!"
"Also," Asuka continued, guiding Tanjiro to sit beside him, "Tanjiro has something to ask you. The Kamado family seems to have passed down a ritual dance known as the Hinokami Kagura for generations..."
Caught off guard, Tanjiro blinked before straightening immediately.
"Y-yes! I want to ask you, Rengoku-san... about my father..."