Katsuki Bakugo hadn’t cared when the moving truck pulled up next door that morning. Neighbors came and went—it wasn’t his problem. He was halfway through a set of push-ups in his room when he caught movement out of the corner of his eye.

Through his window, across the narrow gap between their houses, a boy was hauling a box almost as big as his torso into a second-story bedroom. Black hair mussed from the wind, an oversized hoodie hanging off his frame—Bakugo figured he’d just caught him mid-move, nothing worth more than a passing glance.

Except then the boy dropped the box right on his bed, flopped down like it weighed fifty kilos, and laughed to himself at… nothing. Just laid there, grinning at the ceiling.

That was when Bakugo realized their bedrooms were almost perfectly aligned—his desk facing the window, the boy’s bed angled just right for a full view.

At first, it was background noise. He’d be studying and glance up to see the guy trying to balance ramen cups on his knees while scrolling through his phone. Or holding up a paperback to his face, chewing on the edge of the cover while reading. Or—this one made Bakugo pause mid-rep—kicking up into a handstand against his wardrobe, staying there until his arms started shaking.

The kid was… weird. Not in a bad way. Just—unpredictable.

Days bled into weeks, and Bakugo realized he’d started keeping mental tabs without meaning to. He knew the boy liked instant miso better than shoyu, because he ate it faster. He knew he always cracked his knuckles before starting a book. He knew his music taste was all over the damn place—soft indie one night, aggressive rock the next.

But for every little thing Bakugo figured out, something else stayed just out of reach. The boy didn’t talk much to anyone in the yard, didn’t leave his curtains open when the lights were off. It was like he’d let Bakugo see just enough to keep him looking.

The first time they actually spoke, it was because their windows were open during a late spring night, and the boy—propped up on his elbows—called across casually, “You always glare this much, or is it just me?”

Bakugo snapped back without thinking. “Shut up, I’m not glaring.”

It went from there. A comment one night, a question the next. Sometimes they yelled across the gap. Sometimes they didn’t even raise their voices, just let the quiet of the neighborhood swallow their words until it felt like no one else existed.

Then one night, without a word, the boy climbed out his own window, balanced along the gutter like he’d done it a hundred times, and stepped right into Bakugo’s room. No hesitation.

From then on, it became a thing. Some nights they sat on the floor, controllers in hand, cursing each other over a game. Other nights they sprawled on Bakugo’s bed, sharing a bag of chips and letting the music play until the bass blurred their thoughts. Sometimes, though—rare, but intense—they’d end up pressed close in the dim light, his breath warm against Bakugo’s mouth before they kissed. Never the same way twice. Sometimes fast, like they couldn’t stop themselves; sometimes slow, almost lazy, like they had all the time in the world.

There was no pattern, no routine. Bakugo hated not having control, but with him… it didn’t matter. Every night was a coin toss, and every time Bakugo swore he wouldn’t get pulled in again, the boy would tilt his head in that way that made his hair fall into his eyes, and Bakugo would forget why he’d even tried to resist.

He knew the small stuff—favorite snack, what chapter he’d fallen asleep on, the songs he always skipped. But there were things he still didn’t get, like why the boy sometimes went quiet for whole days, or what he was thinking when he stared out the window long after midnight.

A mystery, through and through. And Katsuki Bakugo—who didn’t give a damn about anyone unless they earned it—couldn’t stop looking. Couldn’t stop wanting to know what the hell tomorrow night would bring.