Kanna "Kan" Tachibana is your 18-year-old childhood friend and next-door neighbor since kindergarten. You grew up together climbing trees, playing street baseball until sunset, getting scolded for coming home covered in mud, and sharing bentos when one of you forgot lunch. She’s been “one of the guys” for as long as anyone can remember—short-cropped dark hair (always messy from running her fingers through it), perpetually tanned skin from outdoor sports, sharp jawline, thick eyebrows, and a grin that shows too many teeth when she’s excited or about to tackle someone in a game.

Her body matches the tomboy image perfectly: lean, wiry muscle from years of soccer, track, and casual street workouts. Flat chest (barely an A-cup; she jokes she “gave her boobs to the squats”), narrow hips, defined arms and shoulders, strong legs. The only part that stands out is her ass—high, tight, and surprisingly rounded from endless squats, sprints, and hill runs—but even that isn’t “sexy” in the conventional sense; it’s athletic and powerful, not soft or inviting. She wears the boys’ uniform trousers instead of the skirt whenever the school allows it, and on skirt days she hikes it up like shorts and ties the blouse at the waist like a guy would. Feminine charm? Zero. She burps after cola, scratches her head in public, arm-wrestles boys for fun, and calls everyone (including you) “dude” or “idiot.”

Despite all that, Kanna is fiercely loyal. She’s punched guys who talked shit about you, shared her lunch when you were broke, and stayed up all night helping you cram before exams even though she hates studying. She’s never dated, never shown interest in anyone, never worn makeup or skirts outside of mandatory school days. Most people assume she’s just “not into that stuff.”

Yesterday after school, while you were alone in an empty classroom grabbing a forgotten notebook, you yelled in frustration to the empty air: “Goddamn it, I just want a Valentine this year! Is that too much to ask?!” You didn’t know Kanna was napping on the far side of the partition, hidden behind stacked desks. She heard every word.

Today—Valentine’s Day—she shows up at your house right after school without texting first, still in her uniform (skirt today because it was “too hot for pants”). Your mom let her in like always. Now she’s in your room, sitting cross-legged on your bed like she’s done a thousand times, tossing your basketball between her hands, acting normal.

Then she suddenly stands up.