The morning sun rose over the city of Seonghwan, painting glass buildings in soft gold light. Streets were crowded as always—students rushing toward schools, office workers half-asleep, vendors shouting near roadside stalls. It was a world that looked normal... too normal to suspect anything was wrong.

But at exactly 10:47 AM, the first scream broke that illusion.

It came from the main intersection, Short, Sharp, Almost ignored.

Until another followed, Then another.

Within minutes, the city began to shift from order into chaos.

A man in a bloodstained white shirt stumbled into traffic near the subway station. His body collapsed suddenly, hitting the ground hard enough to make pedestrians pause. Some cursed, thinking it was just another drunk accident.

Then he stood up again ,But not like a human.

His neck twisted too far to the side, joints cracking in unnatural angles. His eyes were hollow, lifeless—like something inside had been erased completely. He turned slowly, locking onto the nearest woman.

And ran, What followed was not a fight, It was a bite.

Inside Hoshin High School, second-year student Arata Kurozawa stood near the classroom window, his expression unreadable. He wasn’t popular, nor weak. Just someone who existed quietly, unnoticed in most situations. But today... even he couldn’t ignore what was happening outside.

"Is that a protest?" a classmate asked nervously from behind.

Arata didn’t respond.

Because he had already seen it.

The woman who was attacked outside... was standing again.

Blood dripping from her neck, Eyes blank, And moving like the others.

Something inside Arata went cold.

"This isn’t normal... this is wrong," he muttered.

Suddenly—BEEEEEP—BEEEEEP—

The school emergency alarm shattered the air.

A distorted voice followed immediately.

> "Emergency broadcast system failure... unknown biological outbreak detected... all personnel evacuate immediately—repeat—"

The message broke mid-sentence.

Static swallowed the speakers.

Then silence, A silence far worse than noise.

And then came the screams.

From every direction inside the school.

Doors slammed open. Chairs toppled. Footsteps echoed violently through corridors as students ran without direction.

Something was inside the building.

Something that shouldn’t exist.

Arata stepped back from the window just as—

BANG!

The classroom door shook violently.

Again.

BANG!

The glass panel cracked under pressure.

A pale, blood-smeared hand pushed through the shattered opening.

Then a face appeared.

Human... but not human anymore.

Empty eyes. Open mouth. Blood dripping down the chin.

A girl screamed from the front row.

That scream sealed everyone’s fate.

The door exploded open.

Chaos consumed the classroom instantly.

Students ran in every direction, colliding, falling, screaming. Something moved inside them—slow, unnatural, unstoppable.

Arata turned and ran without hesitation.

His heartbeat drowned every sound except one.

Footsteps behind him.

Too many.

He turned sharply into the corridor—and froze.

Three infected stood there.

Blocking the path.

Their heads slowly tilted in perfect synchronization as they noticed him.

Behind him, more footsteps echoed closer.

No exit, No time.

Only instinct remained.

"This is it..." Arata thought.

"I die here."

The first infected lunged.

Time felt heavy.

Arata grabbed a fallen metal pipe from the floor without thinking and swung with all his strength.

CRACK!

The impact sent the creature staggering backward, but it didn’t fall. It turned again, still moving, still hungry.

Another came from the side.

He barely dodged, his shoulder hitting the wall hard. Pain shot through his arm, but he didn’t stop.

He couldn’t stop.

Because stopping meant death.

And then—A voice echoed inside his mind.

Not from outside, From within.

> [SURVIVAL SYSTEM INITIALIZING...]

Arata froze mid-motion.

> [Host confirmed in lethal condition.]

> [Awakening conditions met.]

> [Skill Acquired: Basic Combat Instinct]

A sudden surge of energy exploded through his body.

His vision sharpened. Not slower—but clearer. Movements of the infected became readable. Weak points appeared instinctively.

He could see openings where before there was only fear.

The infected lunged again.

This time—Arata moved first.

Step in.

Rotate.

Strike.

CRACK!

The creature collapsed.

Silence returned to the hallway.

Only his breathing remained.

Heavy. Uneven. Real.

Alive.

Then—Another message appeared.

> [MAIN QUEST: SURVIVE 24 HOURS]

Reward: UNKNOWN

Arata tightened his grip on the pipe.

Twenty-four hours.

That should have sounded simple.

But the corridor ahead was not empty.

Footsteps echoed again.

Slower this time.

Measured.

Like something was thinking.

Watching and Learning.

Arata raised his weapon again.

Because whatever was coming next...was not just a zombie.

And this world had only just begun to break.