The humidity in Tokyo's Ota District was thick enough to swallow a man whole. In the narrow, trash-strewn alleyway behind an abandoned hospital, the air didn't just feel heavy—it felt wrong. It had that greasy, metallic tang that only manifested when a Curse was reaching its breaking point.
Kaito Arisawa leaned against a rusted dumpster, the metal groaning under his weight. He wasn't the "prodigy" type. He didn't have the effortless grace of the Zenin clan or the limitless ego of a Gojo. He was a Grade 2 sorcerer who looked like he'd been dragged through a gravel pit. His Jujutsu High uniform was frayed at the cuffs, and a cigarette—unlit and mangled—hung from his lower lip.
"Don't give me that look," Kaito muttered, eyes fixed on the shadows shifting deep within the hospital's loading dock.
Beside him, a small, bird-like Shikigami—his only constant companion—shivered. It was a pathetic thing, made of thin paper and reinforced with a drop of Kaito's blood. It was a scout, nothing more.
"I know it's a Grade 1," Kaito whispered, finally flicking the cigarette away. "And I know I'm supposed to wait for the semi-first grade backup. But if we wait another twenty minutes, that thing is going to finish digesting the three teenagers who broke in there on a dare. By then, it won't be a Grade 1 anymore. It'll be a catastrophe."
He reached into his tactical vest and pulled out a pair of brass knuckles. They weren't ordinary brass; they were forged from cursed iron, etched with jagged runes that glowed a faint, sickly green when he channeled his energy.
Kaito took a breath. He didn't think about heroics. He thought about the math. Three lives inside. One life out here. If I die, the math stays bad. If I win, the math resets.
He moved.
He didn't run; he blurred. Kaito's combat style was a desperate, high-speed scramble. He burst through the loading dock doors, his boots skidding on slick, black mold. The interior of the hospital was a labyrinth of hanging plastic sheets and overturned gurneys.
Then, he saw it.
The Curse was a nightmare of geometry and flesh—a central, pulsating mass of muscle with dozen of human-like arms protruding at impossible angles. It didn't have a face, just a vertical slit that leaked a fluorescent yellow bile. It was hunched over a pile of medical waste, and tucked beneath its primary limbs were three unconscious forms, wrapped in cocoons of translucent skin.
The Curse sensed him. The vertical slit opened, revealing rows of needle-thin teeth that vibrated with a sound that shattered every glass window in the room.
"Yeah, yeah. You're scary," Kaito gritted his teeth, feeling the sound waves vibrate in his molars. "Let's see if you bleed."
He slammed his fists together. The runes on his knuckles flared. "Technique: Friction Burn."
Kaito lunged. The Curse lashed out with four arms simultaneously, each one moving with the speed of a whip. Kaito twisted his body mid-air, a move that sent a sharp spike of pain through his lower back—an old injury from a mission in Kyoto—but he cleared the strike. He landed on the creature's massive forearm and ran up it like a ramp.
He punched. Once. Twice. Three times.
Each strike didn't just impact; it ignited. His Cursed Energy didn't explode; it caused intense, localized friction within the target's cells. The Curse's flesh began to smoke, then char, then liquefy. The creature shrieked, a sound of genuine confusion, and tried to swat him away like a fly.
Kaito was too fast. He was a mosquito with a grudge. He dove under the main body, his knuckles glowing white-hot now. He aimed for the central mass, intending to blow the core out from the inside.
But the Curse wasn't just a brute. It was evolving.
As Kaito's fist made contact, the creature's flesh didn't resist—it softened. Kaito's arm sank into the Curse up to his elbow, the burning friction being absorbed by the cooling yellow bile.
"Shit," Kaito hissed.
The vertical slit on the Curse's "head" migrated down its body, appearing inches away from Kaito's trapped arm. It opened wide. Kaito could see the throat—a dark, infinite tunnel of teeth and rotting souls.
Crunch.
The sound of his forearm snapping was loud in the quiet ward. Kaito's scream was caught in his throat as the Curse's teeth sank into his bicep. Pain, pure and blinding, flooded his nervous system.
"You... ugly... bastard," Kaito wheezed.
He didn't pull away. If he pulled away, he'd lose the arm and the fight. Instead, he shoved his other hand—the free one—directly into the creature's open maw.
"You want a meal? Eat this."
He didn't use a punch this time. He released every single drop of Cursed Energy he had left in one concentrated burst of friction. He didn't care if he blew his own hand off.
The explosion was muffled, contained within the creature's gullet. For a second, everything was still. Then, the Curse's body began to swell. Internal steam whistled through its pores. With a wet, disgusting thwack, the creature burst, showering the room in boiling bile and shredded muscle.
Kaito was thrown backward, hitting a concrete pillar with enough force to crack it. He slumped to the floor, his left arm a mangled mess of blood and white bone, his right hand charred black.
He coughed, spitting out a mixture of bile and blood. Through his hazy vision, he saw the three cocoons. They were intact. They were moving.
"Math... checks out," Kaito whispered, his head lolling to the side.
He expected the darkness to take him. He expected the silence of the hospital to be his ending. But then, he heard footsteps. Not the heavy, uneven thuds of a Curse, but the rhythmic, confident click of leather shoes on tile.
A man stepped over the remains of the Curse. He was wearing a dark suit, his hair slicked back, and he carried a briefcase that looked entirely too expensive for this hellhole. He didn't look like a sorcerer. He looked like an accountant.
The man stopped in front of Kaito, looking down at the dying sorcerer with a mixture of pity and professional curiosity.
"Kaito Arisawa," the man said, his voice smooth like silk. "The Grade 2 who refuses to die. I've been watching your 'math' for a long time."
Kaito tried to raise his good hand, but it wouldn't move. "Who...?"
"The Higher-Ups think you're a failure because you don't have a Domain," the man continued, kneeling down. He opened his briefcase. Inside wasn't paperwork. It was a single, withered finger, wrapped in seals that looked like they were bleeding. "But my employer sees potential in your desperation. You don't want to die, do you, Kaito?"
Kaito's heart hammered against his ribs. The aura coming from that briefcase was suffocating. It was older than the hospital, older than the city, older than the concept of sorcery itself.
"I... I want to live," Kaito rasped, the instinct of a cornered animal taking over.
"Good," the man smiled, and it was the most terrifying thing Kaito had ever seen. He picked up the finger. "Then let's change the variables of your equation."
Before Kaito could scream, the man jammed the finger into the open wound on Kaito's mangled arm.
The world didn't just go dark. It turned red.