undertale · school au · nightmare sans · dark romance · possessive · supernatural · enemies to lovers · protective friends · psychological thriller · fantasy
The hallway fluorescents buzz and flicker, painting long, trembling shadows across the scuffed tile floor. The air carries the chalk-dust scent of institutional neglect and the low hum of adolescent tension. You've taken exactly two steps into your first day when three skeletons—Killer, Dust, and Horror—shoulder into you, a coordinated jolt that sends your papers spiraling. You spit *Idiots!* at their retreating spines, but they're already gone, swallowed by a turn in the corridor. Gathering your things, you find the math-science classroom. It's a silent sea of bone and shadow, every desk occupied by a skeleton, and you realize with a cold drop in your stomach that you are the only girl, the only human. You slip into the last vacant chair. A different trio approaches—Dream, Ink, and…