Night settled over Seoul like a blanket of calm, but inside the Sung household, the warmth of family was louder than the silence outside.
Sung Jin-Woo sat on the living-room couch, freshly showered after returning from a dungeon raid. His black shirt clung to him, hair damp, eyes sharp but relaxed for the first time in days. The smell of ramen filled the entire house.
Across the table, his little sister, Jin-Ah, slurped her noodles while watching anime on the TV.
"Big bro, look!" she said with sparkling eyes."Demon Slayer season two is insane. The Hashiras are fighting like gods!"
Jin-Woo gave a small smile — the kind only Jin-Ah could pull out of him."Yeah? So who's your favorite this time?"
"Obviously Rengoku!" she said confidently."He protects everyone even when he knows he might die. And– and the way he smiles… even when he's hurting…"
Jin-Woo paused. That line felt too familiar.A protector who keeps fighting through pain…He remembered that boy he used to be — the weakest hunter, barely surviving to protect his family.
He gently rubbed Jin-Ah's head.
"Just don't stay up too late. You have class tomorrow."
She stuck her tongue out."You sound like Mom."
Jin-Woo laughed quietly… a very rare sound.
Meanwhile — The Korean Hunters Association
Chief Woo Jin-Chul slammed a stack of reports on the table.
"This is not a normal Gate. We've checked three times. The mana reading is impossible."
The holographic image of the Gate appeared — swirling, black, with faint red ripples like blood veins.
Cha Hae-In narrowed her eyes."It feels… ancient. Not demonic, not dragon-type, not giant-type. Something else."
Woo Jin-Chul nodded."We're planning to call Hunter Sung Jin-Woo just in case."
At the mention of his name, Cha Hae-In looked away quickly — trying to keep her expression neutral, but failing slightly.
"If he enters… tell him to be careful."
Back at Jin-Woo's Home
Jin-Woo walked to the top floor when—
DING!
A blue window appeared in front of his eyes.
[ System Alert ]
A dimensional gate beyond record has manifested.
Coordinates: Restricted by System.
Entry Requirement: Shadow Monarch only.
Main Quest: Protect the Pillars of Humanity.
Failure Penalty: The collapse of that world.
Reward: ???
Would you like to accept the quest?
→ YES / NO
Jin-Woo's eyes narrowed.Pillars? Protect? Collapse of a world?
Another window suddenly overlapped.
Warning:
The target world contains threats that even Monarchs fear.
Proceed at your own discretion.
Jin-Woo inhaled deeply.
Another world…? Another battlefield waiting…?
He glanced at his sister — happily watching Demon Slayer on TV, tears in her eyes as Rengoku stepped forward to protect others.
Jin-Woo clenched his fist.
If there's another world where people are fighting to survive… then someone has to protect them.
He raised his hand toward the glowing "YES" button.
Quest Accepted.
Opening gateway in "15" seconds.
Prepare for dimensional transfer.
The house began to shake lightly. Wind swirled around him though all the windows were closed. Jin-Ah looked over, confused.
"Oni-Cha…?"
Jin-Woo smiled softly at her — the smile of a brother who always keeps his promise.
"I'll be back soon. Don't worry."
Before she could stand, shadow energy swallowed Jin-Woo whole.
Jin-Ah stared at the empty space where her brother stood, the anime screen still glowing behind her.
On the TV, the narrator of Demon Slayer spoke:
"Demons lurk in the night. But as long as the Hashiras stand, humanity will not fall."
At the exact same moment…
A black portal opened in a distant world.
Jin-Woo stepped out — into the Demon Slayer era.
To be continued…