The laboratory smelled the same.
Metal.Disinfectant.Fear that never washed away.
Mitsuki froze the moment she stepped inside.
Her knees trembled. Her claws scraped helplessly against the floor. The memories came back all at once—white lights, restraints, voices that never said her name.
Rei felt it.
He moved closer without thinking.
"You're not here anymore," he said softly."They don't own you."
Kagami laughed.
"You still don't understand," he said, his body shifting again, scales crawling over his skin like living armor."She belongs to progress."
He attacked without warning.
This time, Rei didn't dodge.
He took the hit.
Bones shattered.
And then—reformed.
His body screamed, rewrote itself, and stood again.
Kagami stared.
Slowly, something close to irritation crossed his face.
"You're degrading," Kagami said."Your evolution has no discipline."
Rei wiped blood from his mouth.
"It has direction."
Mitsuki screamed Rei's name as Kagami lunged again.
She moved before fear could stop her.
She leapt—small, fast—straight toward Kagami's chest.
He caught her easily.
Her body slammed into the floor.
The sound was wrong.
Too final.
Rei felt something inside him tear open.
Not muscle.
Not bone.
Something deeper.
He stopped thinking.
When Rei moved, the world couldn't keep up.
He struck Kagami once.
Just once.
His hand pierced through scales, flesh, and bone—straight into the core of Kagami's ever-shifting body.
The place where evolution kept rewriting itself.
Kagami screamed.
This time, it was fear.
"You don't get it," Kagami gasped, body spasming as his forms collapsed into each other."Without control—evolution devours itself!"
Rei leaned close.
"Then let it."
He tore the core out.
Kagami's body tried to adapt—and failed.
Scales melted. Limbs warped. Flesh lost its shape.
A creature with no identity collapsed into itself, screaming until there was no mouth left to scream from.
Then—nothing.
Silence returned to the lab.
Broken only by Rei's breathing.
And Mitsuki's.
Rei ran to her.
She was alive.
Barely.
Her body had stopped changing. Blood soaked into the floor beneath her.
"Mitsuki—stay with me," Rei whispered, voice breaking.
She smiled weakly.
"I think… this is as far as I go."
"No," Rei said immediately."You said you didn't want to disappear."
"I don't," she said."But I don't want to be hunted forever either."
She touched his chest.
"I gave you everything," she whispered."You can live now."
Rei shook his head violently."I don't want a world without you."
Mitsuki's ears twitched one last time.
Then she leaned in.
Pressed her forehead against his.
Soft.
Human.
"I was happy," she said."That was enough."
Her body went still.
The lab lights flickered.
And shut down.
Epilogue
The incident was erased.
Declared a gas explosion.An illegal experiment.A closed case.
Rei disappeared.
Somewhere far from the city, a boy with sharp eyes and too-quiet footsteps lives in the shadows. He avoids crowds. He listens more than he speaks.
Sometimes, late at night, he feels a phantom warmth beside him.
A tail brushing his arm.
A presence that never fully leaves.
Rei looks up at the city lights and whispers:
"She was a rat."
Then, softer—
"And she taught me how to love."