Spark of Instinct

It had been a week since Shin Karasuma shared dreams and laughter under the trees with his friends.

A week of peaceful mornings, perfect grades, secret late-night training, and stolen naps during math class.

But some mornings didn't stay peaceful for long.

His alarm buzzed at 5:30 AM, like always. Shin sat up immediately, rubbing his eyes as the soft static of his quirk rippled across his fingertips. The energy was familiar now—his constant companion. Not wild or volatile, but steady. Controlled.

He opened his window to feel the breeze as he stretched, then made his way to the kitchen.

"Morning," he greeted, slipping past his dad, who was hunched over his coffee.

"Still acting like you're training for the Olympics," his father muttered.

His mom turned from the stove with a warm smile. "You'll wear yourself out one day, Shin."

"I won't," Shin replied with a small smile. "You'll see."

After breakfast, he stepped outside into the quiet morning air and began his daily workout. A hundred pushups, sit-ups, footwork drills—all while suppressing and controlling the electric charge in his muscles, just below the threshold of visible sparks. It was all part of his discipline, a routine forged from another lifetime.

By 7:00 AM, he was showered, dressed in his neat school uniform, and on his way out the door. His black hair, slightly messy from the towel dry, framed his sharp but soft features—eyes calm, jaw set with focus. He was still just a kid to the world. But Shin Karasuma had lived enough to know how quickly peace could shatter.

And today, it did.

He was just turning the corner near Arai District—three blocks from school—when it happened.

BOOM.

The sound cracked the air, loud enough to set off car alarms.

People screamed.

Glass shattered.

Shin's body moved before his thoughts caught up.

A plume of smoke billowed from the front of the bank ahead. People poured out, stumbling, shouting. Some cried for help, others just ran.

He sprinted forward, slipping between parked cars and knocked-over signs, stopping behind a delivery truck to assess the scene.

One villain. Maybe mid-level. Armor? No... mechanical gauntlets.

The man was huge—at least 6'4", with a wild mohawk and heavy boots. His arms were wrapped in power-charged gauntlets, glowing with unstable kinetic energy. One crackled as he grabbed a terrified bank teller by the arm and shouted at another clerk to fill a bag with cash.

No pros in sight yet.

Shin's heart beat steady. Faster than a normal human. Strength enhanced by the gauntlets. Probably not expecting resistance.

He slipped his bag off, pulled the zipper closed, and crouched low. Sparks coiled along his arms. He didn't have a hero license. This wasn't what he was supposed to do.

But his body didn't care.

He couldn't just watch.

He launched.

The lightning in his legs exploded outward with a loud snap, sending him rocketing forward across the pavement like a blue streak. In the blink of an eye, he was between the villain and the hostage.

The villain flinched. "Huh?! Who the—?!"

Shin didn't answer.

He surged up with a lightning-infused uppercut straight into the man's gauntlet. The metal sparked violently, malfunctioning as it spat unstable energy. The villain grunted in pain and dropped the woman, who stumbled back in shock.

Shin pivoted, spinning into a low kick that cracked against the man's thigh and sent him staggering backward.

"Stupid brat!" the villain snarled, resetting his stance.

Shin's stance was calm, focused. His hands sparked, electricity crackling around his arms like living veins of light.

"I'm not a hero," he said softly. "Not yet. But I won't let you hurt anyone."

The villain charged, gauntlets pulsing—but Shin was faster. He ducked low, moved to the left, and fired a quick jolt into the man's exposed flank. The villain staggered, teeth gritted in pain.

Shin didn't let up.

With a sudden burst of lightning from his soles, he surged forward, driving his knee into the villain's gut. The air left the man's lungs in a heavy oof as he doubled over.

Then, with the speed of a thunderclap, Shin jumped, spun mid-air, and delivered a lightning-charged roundhouse kick straight to the side of the villain's head.

CRACK.

The man's eyes rolled back. He collapsed like a toppled tower, unconscious before he hit the ground.

Shin landed lightly, the energy around him fading into soft flickers.

Sirens echoed in the distance.

The pros were coming.

Time to vanish.

******

Detective Riku Matsuda stepped out of the patrol car just as the sirens died down, the flashing red and blue lights bathing the smoky street in pulses of color. His partner, Officer Ayane Kuroda, was already ahead of him, gun drawn and issuing commands.

"Area's secure. Civilians evacuated," she reported.

Riku's eyes swept the scene—the shattered bank windows, scattered debris, the faint scorched marks on the pavement... and the villain, slumped unconscious in front of the building like a sack of broken scrap. His mechanical gauntlets were still sparking, one clearly melted at the wrist.

"Was this guy neutralized before we got here?" Riku asked, stepping cautiously toward the downed man.

Ayane gave a short nod. "Witnesses say someone stopped him. Fast. Real fast. Blue lightning, they said. Like... a human thunderbolt."

Riku frowned and crouched beside the villain, checking his pulse and inspecting the damage. "No lethal wounds. Just clean strikes. Efficient. Tactical."

"Definitely a quirk user," Ayane muttered. "But no one got a good look. Some civilians said it was a kid. A student."

Riku raised an eyebrow at that.

They hauled the villain to his feet, cuffing him with quirk-dampening restraints. He stirred weakly, groaning, blood crusted at his lip and temple. One eye fluttered open.

"Hey," Riku said, crouching beside him again. "You were about to rob a bank and suddenly got your lights punched out. Who hit you?"

The villain coughed. "Dunno… couldn't see."

"You didn't see who hit you?" Ayane asked, unconvinced.

"Kid moved like a flash," the villain muttered. "Didn't even give me a second. One moment I had the girl, next—bam—shock to the ribs, knee to the gut, then lights out."

He grimaced. "Wasn't a pro. No costume. No name. Just… a blur of lightning and a glare like he meant it."

Ayane and Riku exchanged a glance.

They turned to the bank employees next. The manager, still pale and shaking, gave a similar story.

"Blue lightning," she whispered. "A boy. School uniform, I think. He saved our lives."

"No face?" Riku asked.

She shook her head. "He was too fast. By the time we looked, he was gone."

"Security footage?" Ayane prompted.

They checked the cameras—but every frame that caught the mystery figure was blurred with static and streaks of light. A faint silhouette. Lightning trailing behind him like a comet.

"A vigilante?" Ayane asked, scrolling through the recordings.

"Maybe," Riku said. "But this isn't some reckless amateur. This was someone trained. Someone precise."

He looked back out at the city street, where sunlight was now filtering through the smoke and settling ash.

Whoever that kid was, he wasn't ordinary. Not just because he saved the day—but because he left no trace, no boast, no name. Just a silence that buzzed faintly in the air, like the ghost of a storm.

Riku pulled out his notepad and wrote a single line:

> "Unidentified individual – potential vigilante. Codename: Phantom Spark (temporary)."

Then he paused and muttered to himself, "Or maybe… a spark of something bigger."