Roppongi was a neon-soaked fever dream, a place where the air tasted of ozone, exhaust, and the desperate, cloying scent of cheap perfume. Above the surface, it was a playground for the wealthy and the tourists. But we weren't above the surface.
Underneath the high-end boutiques and the pulsing nightclubs lay a secondary city—a sprawling network of abandoned subway tunnels, fallout shelters, and forgotten drainage systems known as "The Concrete Labyrinth." This was the blind spot of the Jujutsu world. The Higher-ups in Kyoto considered this place a sewer; the mercenaries considered it a sanctuary.
I leaned against a damp brick wall, my breath coming in shallow hitches. My [Cloak of the Fallen King] had long since faded, leaving me in my tattered, blood-stained uniform. Nobara sat on a discarded crate, cleaning her hammer with a piece of her own hem. Between us lay Inumaki, still unconscious, his breathing steady but heavy.
"He's going to wake up soon," Nobara said, her voice echoing hollowly in the tunnel. She didn't look at me. "What are we going to do when he does? He sold us out, Ren. He tried to cage us for a bunch of digital points."
"He was desperate," I said, though the words felt like ash in my mouth. "The System doesn't just offer power, Nobara. It offers miracles. If the Kamo promised to fix his clan's lineage, or heal the damage the Speech does to his body... I can't say I wouldn't have hesitated too."
"I would have," she snapped, looking up, her eyes flashing. "I would have hesitated. But I wouldn't have done it."
[SYSTEM NOTIFICATION]
[LOCATION: ROPPONGI UNDERGROUND - 'THE PIT']
[DANGER LEVEL: HIGH]
[STAMINA: 14%]
A sharp, rhythmic thudding began to vibrate through the floor. It sounded like a drum, but it was too irregular, too violent. It was the sound of flesh hitting flesh, amplified by the acoustics of the tunnels.
"We need money," I said, looking at the flickering HUD in my vision. "And we need a safe house that isn't a damp tunnel. The System says there's a hub nearby. A place called 'The Pit.'"
The Fighting Pit
We left Inumaki hidden behind a heavy iron grate and followed the sound. The tunnel opened into a massive, circular chamber that must have been an old water reservoir. It was lit by strings of industrial work lights and the eerie, multicolored glow of dozens of floating System screens.
Hundreds of people were packed into the tiered balconies—sorcerers with scarred faces, non-shamans with high-tech cursed tools, and "Contractors" who looked more like machines than humans. In the center of the chamber was a sunken ring, the concrete floor stained a permanent, dark rust color.
"Ladies, Gentlemen, and Monsters!" a voice boomed, magically amplified. A man in a pinstriped suit with a prosthetic jaw stood on a floating platform. "Welcome back to the Meat Grinder! Tonight, we have a special treat. A stray dog from the hallowed halls of Jujutsu High has wandered into our den!"
The crowd roared. Every eye in the place turned toward the tunnel entrance. My heart skipped a beat. They knew.
"The bounty on the Void-Walker is currently seventy-five million yen," the announcer grinned, his metal jaw clicking. "But here in The Pit, we have a different rule. If the target wins three rounds in the circle, he earns 'Sanctuary Status.' No one touches him within Roppongi limits for forty-eight hours. If he loses... well, the winner gets the points, and I get the remains."
"Ren, don't," Nobara whispered, grabbing my sleeve. "You're at fourteen percent. You can't even stand straight."
"I don't have a choice," I said, stepping forward. The crowd parted for me like a sea of vultures. "If we don't get sanctuary, the Kamo will find us before the sun comes up. Stay here. If things go south... run."
Round One: The Iron Monger
I stepped into the ring. The air was thick with the smell of sweat and old blood. My opponent jumped down from the opposite balcony—a man twice my size, his arms replaced by massive, steam-hissing hydraulic pistons.
[TARGET: 'IRON MONGER' KANE]
[LEVEL: 35]
[TECHNIQUE: KINETIC STORAGE]
"I've been waiting for a payday like you," Kane growled, the pistons in his arms whirring. "I'm going to turn that 'King's Soul' of yours into a pancake."
The bell—a heavy gong—sounded.
Kane moved with surprising speed for a man his size. He lunged, his right fist glowing with stored kinetic energy. I tried to use [Phantom Step], but my legs buckled. The blow caught me in the shoulder, sending me sprawling across the concrete.
[HP: 38/100]
[WARNING: CRITICAL DAMAGE]
I coughed up blood, the world spinning. The crowd cheered, a wall of noise that felt like it was trying to crush me.
"Pathetic," Valthazar spat. "A King crawling in the dirt for the amusement of peasants. Stand up, Ren. If you can't use your body, use the void."
'I can't... I don't have enough CE,' I thought, my fingers scraping against the cold floor.
"Then stop trying to fight him," the demon whispered. "Let him fight the world."
Kane lunged again, both fists raised for a finishing overhead smash. I didn't move away. I waited until he was inches from impact.
[SKILL ACTIVATION: GRAVITY ANCHOR - INVERSE]
Instead of making myself heavy, I made the ground beneath Kane's feet weightless.
As his massive fists swung down, the sudden lack of resistance threw his balance completely off. He overextended, his own momentum carrying him forward. I reached out and touched his ankle, activating a micro-burst of [Gravity Well].
It was simple physics. I didn't have to overpower him; I just had to redirect him. Kane's own kinetic energy, intended to crush me, was turned into a centrifugal force. He slammed into the concrete floor face-first, the impact shattering his hydraulic arms and cracking the reinforced floor.
The silence that followed was deafening.
[ROUND 1: COMPLETE]
[REWARD: 500 OP]
I stood up, trembling, wiping the blood from my chin. I looked up at the announcer, then at the hundreds of greedy faces in the shadows.
"Who's next?" I asked, my voice amplified by the silence.
The Price of Victory
But as the second opponent—a woman with eyes like a cat and a whip made of human vertebrae—stepped into the ring, the System screen in front of me flickered red.
> [URGENT: SYSTEM OVERRIDE]
> [NEW CHALLENGER HAS BOUGHT THE SLOT]
> [FEE PAID: 5,000,000 YEN]
>
The cat-eyed woman stopped, her expression turning to one of pure terror. She scrambled out of the ring as if the air itself had become poisonous.
A man stepped out of the shadows of the VIP balcony. He didn't jump; he walked down invisible stairs. He wore a tailored charcoal suit and a mask that resembled a weeping oni. In his hand, he held a simple wooden staff.
"The Pit is for children," the man said, his voice smooth and terrifyingly calm. "I am here to collect the debt of the Zenin."
[TARGET: ???]
[LEVEL: ERROR]
[STATUS: ZENIN HEAD CLEANER]
Nobara screamed my name, but a barrier of golden threads—the same technique as Ume's—snapped into place around the ring, cutting me off from the rest of the world.
I was trapped in the circle with a man who made Valthazar go silent.
"My name is Naoya's shadow," the man said, lifting his mask just enough to reveal a mouth twisted into a permanent, mocking grin. "And you, little Vessel, are going to show me exactly what a black hole looks like before you die."
[ROUND 2: BEGIN]