It was an old-style apartment. Though the walls were relatively clean, parts of the paint had already peeled away in patches. But for ordinary civilians living within the cramped interior zones—under such suffocating conditions—no one really cared about aesthetics anymore.
After all, most of humanity's living space had already been devoured by the monsters beyond the Walls. To survive another day was miracle enough. For many living in despair, that was likely their only thought.
"So then, Officer, could you tell me the details of the incident here?" Rentaro Satomi asked, frowning.
"Oh, right..." The rugged middle-aged plainclothes officer pressed the button for the fourth floor, hands in his pockets as the elevator rose.
"...A resident on the third floor contacted us, said blood was leaking down from the ceiling. Given all the evidence—it's definitely a Gastrea. Damn it, at least now that you're here, we can finally go in."
Catching the frustration in the officer's tone, Rentaro turned his head and replied, "Without a civilian police operative present, entry into a Gastrea site is prohibited. That regulation exists to minimize casualties."
"After all, fighting Gastrea can't be done with normal weapons. That's exactly why we exist—the Civil Security operatives."
The law had been enacted shortly after humanity's defeat. It drastically reduced casualties, but of course, no official police officer liked outsiders intruding on their jurisdiction. It was basically saying they were incapable.
Well... perhaps it was true—the Self-Defense Force was useless against Gastrea—but that wasn't something you could say out loud. Thus, the two sides rarely got along. No wonder the officer's attitude toward Rentaro was so sour.
"Tch, that's exactly what pisses me off..." the man growled, scratching his head irritably as the elevator doors opened. He strode out at once.
Then, as if remembering something, he asked, "Hey kid, where's your 'Initiator'? Aren't Civil Security pairs supposed to fight in teams of two?"
"Uh... I suppose I don't really need her help this time..."
Rentaro scratched his cheek awkwardly. After receiving an urgent order from his company president nearby, he had rushed over on his bicycle. But midway through, thanks to excessive speed, he had... accidentally flung his partner off the back seat.
Fortunately, the officer didn't press the matter. Soon, the two reached the target apartment hallway, where a squad of heavily armed security officers stood guard outside the door.
"...Chief!"
The middle-aged officer nodded and stepped forward. "Any updates?"
One pale-faced guard turned with a shaky voice, clutching his communicator. "S-sir... just now, two members of the assault team rappelled in from the rooftop and breached the window... but we lost contact right after that."
The atmosphere froze instantly.
"You idiot! Why didn't you wait for the Civil Security to arrive before breaching?!" The officer grabbed the man by his collar, shouting furiously.
The guard, frightened but defiant, shouted back, "Because we didn't want those Civil Security types stealing our credit! They always look down on us!" He shot a glare toward Rentaro as he said it.
Click—
Seeing their hostile stares, Rentaro sighed softly, disengaged the safety on his handgun, and chambered a round. "Step aside. I'll check inside."
Bang!
With a single powerful kick, Rentaro burst through the door and rushed in. The apartment window faced west—sunset light spilled across his face.
He narrowed his eyes. The small room before him was drenched in crimson. The walls bore cracks and splatters—clear traces of a violent struggle.
The stench of blood invaded his nostrils, forcing his brow to furrow. Two fully armed officers lay sprawled in pools of blood—their bodies motionless, lifeless.
And standing in the middle of the room was a tall, eerie man wearing a burgundy tailcoat and an absurdly high top hat. Most striking of all was the pure white mask on his face, carved with a permanent smile.
There were no signs of any Gastrea—only this figure, standing perfectly still.
Sensing the intrusion, the masked man turned his head and said, "You're quite late... Civil Security officer."
"Who are you? Another operative?" Rentaro Satomi lowered his pistol slightly but remained cautious.
"I am indeed tracking a Gastrea," the masked man replied, slowly turning around to face Rentaro, spreading his arms theatrically. "However... I am not one of your kind, because..."
He tilted his head with a dramatic flourish. "...the killer—is me!"
He hadn't even finished when several armed officers burst through the doorway. Upon hearing his words, they immediately lost control. "You bastard—die!"
Realizing the man was hostile, Rentaro's expression hardened. He lunged forward, throwing a fierce straight punch.
The masked man caught it easily and chuckled. "Not bad at all."
Just as he prepared to drive his fist into Rentaro's abdomen, a sudden buzzing hum filled the room—
Bzzzz—!
Their attention was drawn toward the shattered window, where the entire sky outside turned a blinding shade of violet-red.
The masked man froze mid-motion. Rentaro, the officers, everyone inside—stood stunned by the luminous radiance erupting beyond the glass.
"What... what is that?" gasped the middle-aged officer, his voice cracking as realization struck. "Wait—that direction... that's near the Tokyo Area Monolith perimeter!!"
Before he could finish—
BOOOOOM!!!
The violet-red light swelled rapidly, breaching the horizon in a brilliant surge that stained the heavens. The explosion's glare was so intense it devoured the setting sun itself.
Moments later—
KA-THOOOOOM!!!
Even at such a distance, everyone could only stare in horrified disbelief. The sheer magnitude of the blast was beyond imagination.
Whoooosh—crash!
A violent shockwave tore through the building, flinging Rentaro backward. Bottles and furniture shattered around him, curtains ripped free from their rails with a tearing—shrrrk.
Outside, a violet-red fireball nearly a kilometer wide rose slowly above the Tokyo Area's Monolith perimeter, its blinding radiance eclipsing the very sun.
At that moment, the citizens across the Tokyo Area saw a terrifying sight—two suns blazing in the sky. One distant and golden... the other violet-red and terribly close.
The shockwave ripped up soil dozens of meters deep, sending tremors rippling outward for miles. Nearly half the Tokyo Area felt the earth shudder beneath them.
Crack—
Countless buildings began to shake violently. The apartment complex housing Rentaro swayed like a reed in the wind, the floors undulating underfoot. Webs of cracks spread rapidly across the walls.
Then, from the heart of the inferno, a mushroom cloud over a kilometer wide shot upward—towering ten thousand meters into the air, drawing every eye in the Tokyo Area.
...
At the center of the Tokyo Area, atop the municipal tower, stood a young girl with flowing silver-white hair and gentle lilac eyes. Barely sixteen years of age, her flawless features and soft, serene aura could make anyone instinctively want to protect her.
Yet, the fear etched across her face shattered that illusion.
"Your Holiness! It's dangerous—please, we must evacuate you immediately!"
Indeed, this girl was none other than the highest ruler of the Tokyo Area—Seitenshi.
"...Lord Kikunojou Tendo... what is that? Is it... a Zodiac-class Gastrea invasion?" she murmured, ignoring her attendant's plea. Her delicate hands clutched the balcony railing tightly as she stared at the colossal mushroom cloud rising near the Monolith barrier.
She swallowed hard, voice trembling. She knew—if the Monolith barrier was destroyed, the Tokyo Area would face yet another Great Extinction Event.
Standing a half-step behind her was an elderly man—Kikunojou Tendo, her deputy and political regent. In truth, he was the de facto chancellor, second only to her in authority.
Though he outwardly respected and swore loyalty to the Seitenshi, his domineering personality and rigid ambition made his overreach all too clear.
"Your Holiness, please prepare to take shelter. Leave the defensive measures to me," said Kikunojou Tendo, his aged voice firm yet commanding. Dressed in traditional robes, his posture and gestures adhered perfectly to courtly decorum—but his tone left no room for argument.
Anyone who didn't know better might have thought he was the one ruling the Tokyo Area.
"Then I leave it to you, Lord Kikunojou Tendo..." Seitenshi, seemingly long accustomed to her subordinate's domineering attitude, made no further protest. Silently, she turned and left the balcony.
Once she was gone, Kikunojou Tendo stepped forward, taking command without hesitation. Watching the mushroom cloud slowly disperse in the distance, he barked, "Mobilize the Self-Defense Forces! Notify all Civil Security companies—no matter the cost, seal the breach!"
...
Meanwhile—
BOOOOM—!
The violent tremors gradually subsided.
The old apartment was filled with dust and smoke. Pushing aside the wardrobe that had fallen on him, Rentaro coughed and asked, "Cough... Is everyone all right?"
"Still alive... barely. Damn it, what the hell just happened? The Monolith barrier..." The middle-aged officer, his uniform caked in debris, groaned in pain.
Just then—
Riiing—
The ringtone broke the chaos. It was the masked man.
Instantly, Rentaro tensed. Despite the destruction around them, the masked man didn't attack again. Instead, he answered his phone calmly amidst the swirling dust.
"Hello? Oh, Hibina... I see. I'll regroup with you soon. Wait—what did you say? Escape?"
"Papa! Run away, quickly!"
A young girl's panicked voice rang through the phone. Though it wasn't on speaker, Rentaro's sharp hearing caught every word clearly.
Escape? Why would this masked man need to escape? Reinforcements? What was coming?
The next second—
BOOM—BOOM—BOOM—!!!
A thunderous rumble shook the ground—like countless massive objects descending from the sky, crashing into the nearby residential zone.
Bang! Bang! Boom! Bang-bang-bang! "For Se...le...ne...zzz—"
The rhythmic roar of heavy-caliber gunfire, explosions, and furious battle cries filled the call, before devolving into static.
"Hello? Kohina?! What's happening over there?! Hey—!" For the first time, panic cracked through the masked man's composure.
Crack—crack—
The ground rumbled again. The entire building shuddered violently.
"Danger—get out now!"
CRAAAAASH!
The apartment building collapsed in on itself. In an instant, nearly all the security team members were buried in the ruins.
"...Cough..." Rentaro pushed aside the rubble, his body covered in cuts and bruises. Rising to his knees, he stared blankly at the devastation before him.
"What... happened to this place?"
Where apartment towers once stood, now there was only wreckage, smoke, and death. The air reeked of dust and blood.
Catching his breath, Rentaro muttered anxiously, "Enju... please, be safe."
Just as he steadied himself, a dark red figure flew out of the smoke—the masked man, his elegant hat now gone, tumbling hard into the debris.
THUD—!
Then came a heavy rumble. Three colossal figures burst through the shattered wall, their thunderous footsteps shaking the ground as they approached the fallen masked man.
Each stood nearly 2.6 meters tall, clad in thick, black power armor trimmed with silver. Their presence radiated raw, terrifying power.
Their pauldrons and helmets bore red wing insignias, the chestplate marked with a golden double-headed eagle—and a prominent Roman numeral Ⅰ etched at the center.
Clank! Whirrrr—!
The deep mechanical hum snapped Rentaro's focus. He turned and saw one of the armored giants standing over a writhing civilian—skin cracked, veins blackened, body drenched in blood.
A newly infected Gastrea.
The nearest giant raised his weapon—a massive chainsword, its teeth grinding and shrieking with metallic ferocity.
SHRRRK—!
In a single brutal motion, the blade cleaved downward. Blood sprayed. The half-transformed human was shredded before the mutation could even complete—leaving only a grotesque spider-like corpse, three meters tall with six crimson eyes.
"Hmph. So that's all it was. Disgusting thing," growled the soldier through his helmet, his voice low and metallic.
He swung again—the roaring chainsword tore the creature apart, black ichor splattering across half the street.
It took only one strike. The newborn Gastrea was obliterated.
Incredible... Rentaro thought, stunned. These men—were they human? If so, they had to be reinforcements.
"Hey! Officers! Over here!" Rentaro shouted. "We have survivors trapped under the debris—please, we need assistance!"
"..."