[YandereXReader] The Air You Breathe

The city at night never truly sleeps. It’s a chaotic symphony of distant sirens, the wind howling through the cracks of my 12th-floor window, and the frantic, uncontrolled rhythm of my heart thumping against my ribs.

I sat with my knees tucked to my chest on the worn-out sofa, the ghostly blue light of my laptop the only thing cutting through the shadows. I moved here two weeks ago—a fresh start after a breakup that cost me too many tears. But this so-called "beginning" tasted like pure dread, as if someone were forever standing behind me, exhaling an icy breath against my neck.

It started three days ago. A gift box wrapped in midnight-black silk, perched neatly at my doorstep. No card. No return address. Inside lay a lock of hair, tied with a ribbon as crimson as dried blood.

"My hair...?"

My fingers trembled as I touched the nape of my neck. Yes. The length, the silky black sheen—it was unmistakable. Someone had been close enough to shear a piece of me away without me even knowing. A wave of nausea surged up my spine, like a centipede crawling over my skin. He wasn't just stalking me, he was in my sanctuary.

Tonight, the sensation of being watched grew suffocating. I stood up, bare feet pressing against the frigid hardwood floor, intending to check the deadbolt for the tenth time tonight.

Click.

A faint sound drifted from the balcony. I froze, my breath catching in my throat. The sliding glass door—which I could have sworn I locked tight—was slightly ajar. The wind whistled through the gap, making the sheer curtains flutter like a ghost.

In the dim light, a foreign scent hit me. It wasn't cheap room spray, it was the cloying sweetness of lilies tangled with the sharp, metallic tang of blood.

"Who’s there?" My voice cracked, thin as parchment paper.

No answer. Instead, something far more terrifying: a whistle. A melancholy, distorted melody bleeding from the darkest corner of the living room. Each note felt like a needle pricking my eardrums, dripping with a twisted, obsessive devotion.

"Y/n... you forgot to lock the door again. So careless."

A tall silhouette detached itself from the shadows. It was Eric—the charming neighbor from 1202, the man who always offered a polite smile and helped with my groceries. But the smile he wore now held no warmth. His eyes shimmered with a sickly, feverish light, reflecting my own trembling reflection.

He wasn't holding an instrument. In his hand was a surgical scalpel. The blade caught the blue light of the laptop, casting sharp, cold jagged lines across his face.

"How... how did you get in here?" I stumbled back, my hip hitting the edge of the wooden table. The sharp jolt of pain cleared my head for a split second.

Eric took a step forward, his movements as fluid and silent as a predator stalking its prey.

"I’ve been here all afternoon, Y/n. Under your bed. I heard you tossing and turning. I heard you call out your ex's name in your sleep..."

He tilted his head, the scalpel slicing through the air as if caressing an invisible form.

"That didn't make me happy. Not at all. So, I paid him a visit. That pathetic little stalker who kept lingering under your window? He won't be bothering you anymore. Only I... only I am worthy of protecting you from this filthy world."

Eric closed the distance until I could feel the heat radiating from his body. He raised a hand clad in a blue medical glove, stroking the shorn hair at the nape of my neck. His eyes were wide with a terrifying, cult-like adoration.

"Don't be afraid, Y/n. I won't let you be lonely. From now on, I will be the air you breathe. I will be the darkness that envelops you..."

The cold steel of the scalpel grazed my tear-stained cheek. Eric let out a soft, low chuckle—the sound of a man who had completely abandoned his humanity.