Near a road in Shiga Prefecture, there's a barely marked turnoff that leads to a quiet area, surrounded by green fields and gentle hills that highlight the natural landscape.
The road is long and silent, and as you continue forward, massive structures begin to appear, clearly visible from a distance.
These buildings stretch across a vast area, so large they could be compared to a small town. They're long, wide, and light gray. There are no decorations or complex designs—everything about them is purely functional. The real intrigue lies inside.
Before reaching the main buildings, there's a parking area and a security checkpoint, accessible only to authorized personnel. Off to the side, a small lake adds a touch of calm to the setting, like a quiet corner in the middle of a space dedicated to observation and simulation.
Once inside the perimeter, the massive buildings of the complex come into view. Each one is designed to study different natural conditions, such as earthquakes, heavy rain, or extreme winds.
However, one building stands out due to its sheer size and design: a colossal hangar, longer and taller than any other in the area. It has no windows—just enormous metal gates that remain shut almost all the time.
Inside the hangar, the interior feels completely out of place. It resembles a small city: houses, power lines, streets, traffic signs, even vehicles. Everything is built using the same materials and dimensions as real urban areas in Japan. It's not a scaled-down model—it's a full-sized replica, ready to be put to the test.
And what's the purpose of recreating an urban environment inside a sealed structure?
The answer is easy to guess.
This is where the impact of extreme winds is simulated. At one end of the hangar, a series of massive fans are ready to generate air currents that mimic the force of a tornado.
In short, it's a large-scale wind tunnel designed to observe how real structures behave under extreme weather conditions.
Now that the function of this place has been explained, another question arises:
Why does the lab look so utterly deserted at this time of day?
Is Saturday just a bad day for science?
Did the scientists decide to have lunch far away, even with a cafeteria nearby?
Did they go on strike because another hundred-million-yen budget wasn't approved?
If any of these ridiculous theories crossed your mind, I'm here to tell you—they're all wrong.
The truth is much simpler…
The head of the lab received a phone call. A voice from someone high up the chain of command, in a tone that left no room for argument, gave a clear order:
"Evacuate."
And upon hearing those words, the lab chief responded with the only thing that came to mind.
"…?"
But one direct threat to his job—and his entire career—was enough to stop any further questions. In less than ten minutes, every member of the staff had left the premises. Even the insects seemed to sense that something terrible was coming… and flew off without looking back.
Meanwhile, somewhere else in Japan, a blonde-haired woman—one who could be described in hundreds of words—was carefully weighing her options regarding the lab controls she could access remotely.
JB, with full control of the systems from her computer, was scanning the lab's systems.
JB would never trust some random boy claiming that something truly dangerous was about to reach a city—but since it was Asako who confirmed the information, she had no choice but to use all her influence to establish a location where that dangerous thing could be neutralized.
And so, JB pulled strings, flipped switches, and called in every favor until the lab was completely emptied.
Even so, the more time passes, the more she starts to believe that the guy named Desmon isn't going to show up.
"What if he really died?" She mutters under her breath.
Right at that moment, one of the security cameras picks up movement, showing a white-haired, half-naked guy sprinting through the halls of one of the labs-turned-rest areas like he owns the place.
JB blinks a few times, as if questioning the reality of what she's seeing.
The mental image she had of the guy she talked to on the phone... matches alarmingly well with what's on the screen.
After all, who else would walk into a lab half-naked on a Saturday afternoon?
-I seriously want to know how things ended up like this…
Those questions will have their time, but right now, there are more pressing matters.
"You're Desmon, right?"
Her voice rings clearly through the lab's speakers.
The guy comes to a sudden stop, turns toward the camera with a relaxed expression, and raises a hand.
"Yep. I'm Desmon, your friendly neighborhood demon hunter." His tone is casual, as if he hadn't just been running for his life minutes ago. "You must be JB. Nice to hear you… Though, if you can see and hear me now, I guess I'll have to think carefully about how much I'm charging for this."
Desmon's rates are flexible—ranging from a piece of candy to an obscene amount in yen. It all depends on his mood.
"I haven't forgotten what I promised." JB replies with a sigh, though he can't see her shaking her head. "So, where's the dangerous thing that made me evacuate the entire place?"
"If you mean that dumb smoke demon… it should be arriving any minute now. I managed to lose it after, well, a couple of mountains vanished. Actually, wanna hear how I survived a situation I definitely should've died in?"
"Another time.'' JB cuts him off without even pretending to be interested.
"Oh, come on! It's a great story!"
"I'm busy. It's not every day I have to learn how to manage an entire lab in under thirty minutes."
Ever since Desmon mentioned needing to create tornado-level winds, JB had buried herself in the lab's databases, protocols, and operating theories like she'd been working there for years.
No wonder she's climbed so high in the government ranks.
"Good point…" Desmon admits, scratching his neck.
With no one else to share his epic tale with, Desmon shrugs and continues down the lab's halls.
"Maybe Shizuka would want to hear about my great escape…" He mutters with a half-smile. "And that weird thing that happened when I landed…"
A simple, pointless anecdote… or a key piece that'll make sense later?
With that thought lingering in his mind, Desmon stops in front of a wall map of the facility. He scans it quickly and heads toward the locker rooms. One thing is certain—he's not about to face his final battle with Kagenra in his underwear. With only a scrap of cloth covering his groin, he looks like a full-on exhibitionist. Not that he does much to deny it…
Luckily, the locker rooms are well stocked with spare outfits. He doesn't hesitate. In seconds, he walks out in fresh clothes: a blue shirt, black dress pants, a white lab coat, and thick-framed glasses. Not his style, but at least he looks slightly less out of place.
"If we derive the hypotenuse with respect to the inverse sine and multiply it by the least common denominator… we get the negative value of an isosceles triangle minus the derivative of the variable." Desmon says in an expert tone, as if he actually knows what he's talking about.
"I have no idea where you pulled that from… but absolutely all of it is wrong." JB chimes in through the speakers, equal parts confused and resigned to the 'brilliance' of the demon hunter.
"Guess the glasses don't make me smarter." Desmon replies, taking them off and tossing them aside. "By the way, weren't you busy doing research?"
"This place has way too many dangerous things to leave you unsupervised." JB responds seriously.
She's right to be cautious—Desmon was already about to go looking for interesting stuff and maybe press a few buttons just for fun.
"Kyaaa! JB, you pervert! You might see my body, but you'll never have my heart!" Desmon shouted, like a maiden whose honor had been violated.
On the other side of the screen, JB frowned.
"You do know there aren't any cameras in the locker rooms… right?"
"Oh, come on! Can't you play along for once? You're so boring."
"Yeah, yeah… whatever you say…" JB sighed, already drained by Desmon's nonsense.
It wasn't that she lacked a sense of humor. Under normal circumstances, she wouldn't hesitate to humor Desmon for a while. But with danger looming, no one could blame her for not being in the mood.
-Now I get why Asako always sounded so exhausted when talking about this guy, JB thought.
And yet, Desmon's carefree attitude… kept things grounded. It was strange—but effective—at calming the atmosphere.
"If you don't mind, I'll head to the cafeteria and make myself a sandwich. Since the demon seems to be taking its sweet time…"
But JB's voice cut him off before he could take a step.
"…Huh? What is that?"
Desmon stopped, a smirk curling his lips.
"Looks like the guest of honor finally found me."
Through one of the external cameras, JB watched with growing unease. Something… something massive was approaching the lab's entrance.
An impossible silhouette.
Defying all logic, JB saw a colossal figure made of black smoke, with molten fragments of volcanic rock jutting from its body like living flesh. Its face—a demonic mask grotesquely fused with its skin—radiated a crimson glow that burned from deep within. Its limbs were monstrously muscular, ending in massive, razor-sharp claws ready to tear through anything in their path. Its very presence radiated menace, as if fear and death themselves had taken shape.
JB blinked.
Once.
Twice.
Three times.
Was she hallucinating? Had the camera somehow picked up a scene from a horror film?
But no matter how much she tried to reason it away—the creature remained.
Then, with a single motion, the demon raised a claw. In the next instant, gigantic spikes burst from its fingers and launched forward with violent force. The lab's entrance was reduced to rubble in seconds, the camera feed going dead.
"…Can you really destroy something that defies all logic?" JB muttered, a chill running down her spine. Her mind scrambled to recall every piece of supernatural knowledge she'd ever read. Anything. Anything that might help.
Though she was cold, methodical, and trained for high-level crises, JB couldn't stop it—an overwhelming sense of helplessness began creeping in. She could handle any human threat. But this… this was something else. There was no manual, no protocol, no training that could prepare someone for what she was now witnessing.
For one moment—just one—her mind went blank.
And then, a familiar voice broke through the fog, snapping her back to reality:
"HQ to JB! Are you still with us!?"
The sound of the lab being torn apart left no room for doubt. Desmon's "best friend" had officially arrived. What else could hate him so much… after knowing him for less than an hour?
"This is way beyond any protocol…" JB muttered, eyes fixed on the screens. Her voice was tense, yes, but steady. Even she, despite never having faced the unexplainable, regained her composure quickly. Thanks to him.
Hearing Desmon's voice—calm, even nonchalant in the middle of chaos—had a strange effect. It made you feel like things were under control. Because if that idiot could stay calm, then why couldn't you?
"I tried blowing it away with a tornado I made myself. Guess it wasn't strong enough to fully undo it. Now do you understand why I asked you for that favor?" He said confidently, as if his next move would guarantee victory against the demon.
JB, after seeing the demon with her own eyes, finally understood the demon hunter's words: only something capable of creating winds as powerful as the most destructive tornadoes on record could undo that monstrosity. The only real chance of destroying it.
"I get it." She said seriously. "But I need more time. I'm still finishing the system analysis."
"Don't worry." He replied with a smirk. "Grab a cup of coffee, go take a walk… I'll buy you all the time you need. Maybe I'll chat with the demon about the weather."
Fighting something you can't hurt, with nothing but dodging and running, wasn't exactly Desmon's idea of fun.
-Maybe I should ask Enzo for another of Dante's weapons… Nah, I already went broke just to get Alastor, and don't even get me started on the other expenses…
It was definitely time to get a new devil arm. Otherwise, he wouldn't survive if he kept running into demons that couldn't be damaged the usual way. And knowing Desmon's luck, it was bound to happen again.
"You're not the only one having a hard time! I have to read and understand how machines work that I didn't even know existed!" JB complained.
It wasn't quite the same as fighting a demon, of course… but in their own way, each had their job to do.
"Alright, alright." Desmon said calmly. "We all have rough days. You handle that. I'll take care of our annoying guest."
He didn't have to wait long.
The walls near Desmon exploded into pieces, and through the cloud of dust emerged Kagenra.
"YOU CAN RUN, BUT YOU WON'T ESCAPE ME!"
"Are you sure you weren't my ex in a past life?" Desmon said with sarcasm, stepping forward. "You're just as clingy… and I've never even had one. Hahaha!"
-Should I be flattered a demon is this obsessed with me… or worried that it's the closest thing I've got to someone who cares?
Ignoring the fact that Kagenra would make a perfect yandere if it were human, Desmon glanced toward one of the cameras with a more serious look.
"Do me one last favor, JB."
"What do you need?" She replied, raising a brow as she watched him face the demon… unfazed, like it was just another part of his daily routine.
-Is he really going to fight that thing…?
She had a lot to do, but she couldn't look away. Watching a human take on something like that… it wasn't something you saw every day.
"I work better with music." Desmon said with a grin.
"Whatever you say."
JB quickly typed a few commands and picked a random song from the system. The speakers were about to come alive.
Desmon stretched, rolled his shoulders, and made a mocking gesture toward the demon.
"So, stupid smoke demon… this will be our final round. You ready?"
"ARE YOU?!"
"I'll take that as a yes. Come on then, let's have some fun!"
"I'LL KILL YOU!!!" Kagenra roared with such violent fury that the entire room shook.
"Only one of us is walking out of here alive… and I promise you, it's going to be me!"
And without waiting for a bell to ring… Kagenra charged.
The final battle between these two is finally reaching its climax… but the one who decides the outcome won't be either of them.