The ocean had always terrified Kang Joon-hyuk.
Not because of its vastness, nor because of the countless creatures lurking beneath its surface, but because of its silence. Standing on the shoreline, he often felt like the sea was watching him, waiting, holding its breath.
That morning, the silence felt heavier than usual.
Joon-hyuk stood on the cracked rooftop of his apartment building in Busan, staring toward the distant horizon. The sky was an unnatural gray, as if someone had drained all the color from the world. Even the seagulls, usually loud and annoying, had vanished.
Behind him, the metal door creaked open.
"Oppa, are you spacing out again?"
A small hand tugged at his sleeve. Kang Ha-rin, his thirteen-year-old sister, peered up at him, her brows knit together in worry.
He forced a smile. "Just thinking."
"You always say that when something's wrong," she muttered.
Before he could reply, their mother's voice echoed from below. "Both of you, come down! Breakfast is getting cold!"
"Coming!" Ha-rin shouted back before looking at her brother again. "Dad said there might be heavy rain today. The news keeps talking about abnormal ocean patterns."
Joon-hyuk's gaze drifted back to the sea.
"It's not rain," he whispered.
"What?"
"Nothing. Let's eat."
---
The Kang family lived simply.
A small apartment, second-hand furniture, hand-me-down clothes, and careful budgeting. Joon-hyuk's father worked long hours at the docks, while his mother did part-time cleaning work. Money was always tight, but their home was warm.
It was the only reason Joon-hyuk endured his exhausting routine.
After breakfast, he helped his father repair a broken cabinet hinge. His mother packed lunch boxes. Ha-rin prepared for school, humming softly.
Normal.
Painfully normal.
At exactly 10:47 a.m., the world ended.
It began with a low, distant rumble.
At first, Joon-hyuk thought it was an earthquake. The floor trembled beneath his feet, the windows rattling violently. Plates slid across the table, crashing onto the ground.
Then came the scream.
Not from a person—but from the ocean.
A deafening roar erupted outside, as if the sea itself had risen in fury. Joon-hyuk rushed to the window, his heart slamming against his ribs.
The sight stole his breath.
The horizon had disappeared.
A massive wall of water towered above the city, blotting out the sky. It wasn't a wave—it was a moving mountain, advancing toward Busan with unstoppable force.
"Tsunami!" someone screamed outside.
His mind went blank.
"Mom! Dad! Ha-rin!" Joon-hyuk shouted.
They rushed toward him, panic flooding their faces.
The wave struck before anyone could react.
The building shuddered as if hit by a god's hammer. Glass shattered. Concrete cracked. The world flipped upside down as water smashed through windows, swallowing rooms in seconds.
Joon-hyuk barely managed to grab Ha-rin before the current ripped them apart.
Cold.
Dark.
Violent.
Water crushed his lungs. His vision blurred as debris slammed into his body. Somewhere in the chaos, he felt his sister's grip slipping.
"No—!"
He wrapped both arms around her, holding her close, kicking desperately.
A sharp impact smashed into his head.
Then—
Nothing.
---
When consciousness returned, pain followed.
Joon-hyuk coughed violently, expelling seawater as he lay sprawled across twisted metal and shattered concrete. His entire body screamed in agony.
"Ha-rin…?"
He forced his eyes open.
They were on the remains of a collapsed building, floating amid a vast ocean of debris. Cars drifted past. Broken furniture. Pieces of rooftops. The city was gone.
But Ha-rin was still in his arms.
She was unconscious, but breathing.
Relief crashed over him so hard he nearly sobbed.
"Thank God…"
A distant cry echoed across the water.
His father's voice.
"Joon-hyuk!"
His head snapped up.
On a partially submerged bus about thirty meters away, his parents clung desperately to the roof. Water surged violently around them, threatening to rip them away at any moment.
Without hesitation, Joon-hyuk shoved a broken plank into the water and kicked forward, pushing the debris toward them.
Each stroke felt like his muscles were tearing apart.
Just as he reached the bus—
A massive shadow passed beneath them.
The water churned.
Then something colossal burst upward.
A monstrous sea creature, its body longer than the bus itself, slammed into the wreckage. The impact shattered metal, flinging his parents into the raging current.
"Mom!"
"Dad!"
Their screams were swallowed instantly.
Joon-hyuk tried to reach them, but another wave smashed him backward. His fingers grasped empty water.
They vanished beneath the sea.
His mind shattered.
---
Something inside him broke.
The world blurred as grief, rage, despair, and terror crashed together.
He didn't notice the glowing blue text until it hovered directly in front of his eyes.
---
[Emergency System Activation Detected]
[Candidate Mental Threshold: EXCEEDED]
[Survival System Initializing…]
---
"What…?"
His vision trembled.
---
[System Bound to Host: Kang Joon-hyuk]
[Primary Objective: Protect Bloodline — Younger Sister: Kang Ha-rin]
[Secondary Objective: Survive the Ocean Apocalypse]
---
A sharp pain pierced his chest.
---
[Starter Package Granted]
[Ocean Survival Kit ×1]
[Beginner Quest Issued]
---
The screen shifted.
---
Beginner Quest: First Shelter
Objective:
Secure a floating structure capable of housing two survivors for at least 24 hours.
Reward:
• Basic Material Pack ×3
• Energy Recovery Potion ×1
Failure Penalty:
• System Shutdown
• Host Survival Probability: 0.7%
---
Joon-hyuk stared in disbelief.
System?
Quest?
But the violent waves, the dead city, the endless ocean—this was no dream.
Ha-rin stirred weakly in his arms.
"Oppa…?"
His heart clenched.
"Don't worry," he whispered, forcing calm into his voice. "I'm here."
The floating wreckage around them suddenly seemed different. Not just debris—resources.
His gaze locked onto a large overturned cargo container drifting nearby.
A shelter.
"Alright," he murmured, gripping the broken plank tighter. "Let's survive."
And for the first time since the apocalypse began, Kang Joon-hyuk moved forward—not in panic, but by purpose.