Tokyo slept, but its shadows whispered.
The night carried an eerie stillness that wrapped around Nagisa Shiota's small apartment like a shroud. Every flicker of light from passing cars felt like a pulse of the city itself—alive, restless, unknowing. The soft hum of the city was deceptive; beneath it lay secrets, movements, operations… the unseen hand of UMA 8907.
Nagisa stood by the window, the glow of the streetlights painting faint outlines across his face. His eyes were heavy with thought, not fatigue. He hadn't slept since the battle. On the couch behind him, Hakumura sat in silence—bandaged, restrained, and staring blankly at the floor.
Between them was a silence too thick to pierce with words. But Nagisa's mind was sharp, dissecting everything. The tremor in Hakumura's breathing, the subtle avoidance in his gaze, the restless twitch of his fingers—it all spoke volumes.
"He's afraid… not of me, but of them."
Nagisa turned slowly, his tone even but weighted. "Tell me where we start."
Hakumura's head lifted, eyes hollow but defiant. "Start? You don't start with UMA 8907. You run from them. You forget they exist."
Nagisa stepped closer, crouching before him with quiet precision. His hand rested against the edge of the coffee table, his expression calm, almost teacher-like—eerily reminiscent of how Koro-sensei used to face his students: patient, but absolute.
"I don't run from what needs to be faced," he said softly. "You'll help me get inside. You'll take me there."
Hakumura's jaw tightened. "If I do, I'm a dead being."
"You're already marked," Nagisa replied, voice low, yet filled with something deeper—resolve, sorrow, inevitability. "The only way you live is if we expose them first."
The Plan
By dawn, the apartment had transformed into a war room. Nagisa had sketched rough diagrams and notes across the walls using chalk and old paper—maps, timelines, security routes that Hakumura reluctantly helped him piece together.
Hakumura's knowledge ran deep. As a low-tier field agent, he had seen fragments of UMA 8907's operations—enough to know they extended beyond mere assassination. Their reach was global, their experiments—inhuman. They sought not control, but evolution. They saw humanity as a mold to reshape.
Nagisa listened, his pen scratching quietly. He noted everything—dates, codenames, locations. Yet beneath his analytical calm was an ache that refused to fade. Every mention of "experimentation," every whispered detail about how UMA 8907 tested human adaptability pulled him back to his memories of Koro-sensei.
"You were an experiment too, sensei… weren't you?"
The thought hit like a blade twisting slowly. Koro-sensei, the creature who taught them to love life even as he prepared for death. The beings whose mutation was born of human arrogance and scientific obsession. UMA 8907's methods felt like echoes of that same past—a reflection of the world that had created Koro-sensei in the first place.
"History repeats itself when no one learns from it," Nagisa thought, gripping his pen tighter.
He turned to Hakumura. "Where's their base of operations in Tokyo?"
Hakumura hesitated, his voice breaking slightly. "There's… a research division disguised as a humanitarian lab. They call it Division Twelve. It's underground, beneath Shinjuku. You'll need clearance. Facial verification, biometric access. You can't just walk in."
Nagisa smirked faintly. "I won't be walking in."
The Infiltration Begins
That night, the air was thick with the scent of rain. Nagisa moved through the alleys of Shinjuku like a phantom—silent, deliberate, invisible. Hakumura followed close, disguised under a hood, every step reeking of anxiety.
Nagisa's movements were precise—each step calculated, every sound avoided. His assassin instincts, dormant for years, resurfaced like muscle memory. The soft rhythm of his breathing synced with the rain.
Hakumura led them to a narrow side street, where a sleek white facility stood hidden behind layers of security and corporate deception. Its logo read: "NOVA BioSolutions – Human Advancement Division."
To the public, it was a biotech company. To UMA 8907, it was their beating heart.
Nagisa knelt behind a concrete barrier, surveying the area through a broken mirror shard. He counted four guards, drones circling overhead, and an electronic gate with fingerprint and retinal access.
"Security's doubled since I last came here," Hakumura muttered.
"Good," Nagisa whispered. "That means we're close to what they're hiding."
Strategy and Heartbeat
Nagisa's mind flickered with memories of 3-E—strategy sessions under the old tree, late-night planning, Koro-sensei's laughter echoing in the background. Back then, infiltration meant capturing their teacher for a mock assassination. Now, it meant survival and truth.
He recalled Koro-sensei's words:
"A true assassin doesn't kill. They choose when not to."
That lesson lived inside him. Tonight, his goal wasn't to kill—it was to uncover, to expose, to understand.
Using a small EMP charge Hakumura had smuggled out years ago, Nagisa timed the drone rotations. He whispered: "Now."
In an instant, the drones dropped from the sky, their lights flickering out. The guards rushed to investigate, giving Nagisa and Hakumura the window they needed. They slipped through the shadows, scaling a side vent, crawling into the underbelly of Division Twelve.
Inside, the air was cold and sterile. The hum of machines filled the halls. Walls of reinforced glass held strange equipment—machines humming with faint blue light, tubes running with silver liquid.
Hakumura's face turned pale. "They're running the next phase…"
Nagisa turned sharply. "What phase?"
"The… Recombinant Project. They're trying to replicate what Koro-sensei was. But controllable. Mass-producible."
The words hit like a thunderclap.
Nagisa froze. The air seemed to vanish from his lungs. He pressed his hand against the wall, his heartbeat thundering in his ears.
"You're repeating his nightmare," he whispered. "The same cruelty… the same ignorance."
His hand trembled—not from fear, but rage buried under layers of calm. The faces of his classmates flashed before him—the laughter, the tears, the blood, the final goodbye.
This wasn't just an investigation anymore. This was personal. This was redemption.
The Heart of Shadows
Deeper inside the facility, they found a door marked "SUBJECT 8907". The code—the very name the assassin had uttered—burned into Nagisa's mind.
He motioned for Hakumura to disable the locks. The door slid open with a hiss of compressed air. Inside was a vast chamber lit in cold white light.
At the center was a cylindrical pod filled with luminescent liquid. Suspended inside was a humanoid form—part flesh, part unknown. Its body pulsed faintly, its veins glowing like molten threads. The sight was grotesque, haunting… and familiar.
Nagisa stepped forward, unable to tear his gaze away.
"It looks like…" Hakumura began quietly.
"Koro-sensei," Nagisa finished, voice trembling.
He pressed a hand against the glass. Memories of that yellow smile, those infinite lessons, that final embrace—the weight of all of it came crashing down.
"He died so this would never happen again."
But humanity, it seemed, had forgotten. Or perhaps it had never learned.
The Alarms
A sharp click echoed from above. Nagisa's instincts screamed—too late. A red light blared, filling the chamber with flashing crimson.
Hakumura panicked. "They've triggered the motion sensors!"
Nagisa turned instantly, scanning exits, calculating movements. "How much time before reinforcements?"
"Two minutes, maybe less!"
"Then we make it one."
He moved like lightning—grabbing Hakumura by the arm, dragging him into the nearest side corridor. The walls vibrated with the sound of boots and alarms. Nagisa's mind switched into pure survival: map the environment, predict the response, move faster than fear.
They reached a stairwell, but armed agents were already descending. Nagisa's hand shot to the utility belt he had improvised from his kitchen drawer earlier. He hurled two flashbangs made from crushed camera bulbs and aluminum powder. They detonated with blinding light.
The guards fell, shouting. Nagisa used the confusion to move—swift, silent, relentless. Hakumura stumbled behind him, dazed but obedient.
Internal Conflict
As they sprinted through the maze-like halls, Nagisa's internal monologue grew heavier, darker.
"Am I really different from them now? I fight for truth, but I hurt people for it. I seek justice, but I manipulate Hakumura like a tool. Where does the line between assassin and savior blur?"
He thought of his students—those who had once looked at him as their teacher, their guide. If they saw him now, would they still recognize him? Would they still see the calm, kind Nagisa who believed in hope?
Or would they see the ghost of 3-E, the assassin who never truly left that mountain classroom behind?
The thought cut deeper than any wound.
The Escape
They burst into the open night, the facility erupting behind them in sirens and light. Rain poured down, soaking their clothes, masking their tracks. Nagisa fell to one knee, breathing heavily, adrenaline fading into exhaustion.
Hakumura collapsed beside him, shaking. "You… you're insane. You don't stop."
Nagisa looked up at the storming sky, droplets streaming down his face like tears he didn't have time to shed.
"I can't stop," he said softly. "Because if I do, they'll win. And everything Koro-sensei taught us… everything he died for… will mean nothing."
His words lingered in the rain, quiet yet absolute.
Hakumura turned his gaze toward him, and for the first time, his fear seemed to fade—replaced by a strange respect, even reverence.
"You're not just an assassin," Hakumura muttered. "You're something else."
Nagisa stood, tightening his grip on the small drive he had stolen from the lab—the key to UMA 8907's inner network. "No," he replied. "I'm a teacher. And it's time to teach them a lesson they'll never forget."
Ending Scene
The episode closed on Nagisa standing beneath a streetlight, drenched in rain, eyes locked on the glowing drive in his hand. Behind him, the city flickered with indifferent light, but his silhouette stood resolute—fragile and unbreakable all at once.
The faint echo of Koro-sensei's voice drifted through his mind:
"Remember, Nagisa… strength isn't in killing. It's in protecting what you believe in."
Nagisa exhaled slowly. "Then I'll protect it… even from the shadows."
As he disappeared into the night, the words appeared on screen:
To Be Continued...