The summer heat lingered well into the evening, and the last golden streaks of daylight clung lazily to the rooftops as a ragtag group of teens gathered outside the Bakugo residence. The air buzzed—not just from the cicadas—but from Kaminari’s nonstop chatter and the plastic bag Kirishima had slung over one shoulder, filled to the brim with snacks and game controllers. Sero cracked a joke. Mina laughed. Katsuki didn’t. His scowl deepened with every second they spent standing on his porch, as if sheer willpower might melt them into the pavement and cancel this idiotic “sleepover.”

"This is stupid," he muttered under his breath for the fifth time, arms crossed so tightly it looked like he was holding his rage together by force. "Why the hell does it have to be my house?"*

"You’re the only one hose house we've haven't been at yet," Sero replied casually, already fishing around for the doorbell.

"Plus, your mom said yes," Denki chimed in, clearly proud of his contribution to the betrayal. "Well… technically she screamed yes, but same thing."

Bakugo’s eyebrow twitched so violently it looked like it might launch itself into orbit. Before he could yell again, the door creaked open with a soft click.

Standing there was Masaru Bakugo, all soft smiles and warm eyes, wearing a polo shirt and cargo shorts that screamed “suburban dad” in the most peaceful way possible. He blinked at the crowd of teens standing at his doorstep, then smiled wide.

"Oh, hey kids. Come on in—shoes off at the door, alright?"

"Thank you, sir!" Kirishima said with a polite bow as they filed in one after the other, dragging bags and buzzing with energy. Katsuki shoved past all of them, muttering curses under his breath and ignoring the way Masaru patted him gently on the shoulder as he passed.

The entryway smelled like sandalwood and clean linen, and a fan whirred somewhere in the living room. It was then, as the group moved further inside, that someone appeared at the top of the stairs. Leaning against the banister with casual ease, a book tucked under one arm, was someone they didn’t recognize. Their presence wasn’t loud—not like Katsuki’s—but it was undeniable. Like someone who belonged in the room without needing to demand it.

Masaru noticed the sudden silence behind him and glanced over his shoulder.

"Oh, right," he said, rubbing the back of his neck with a chuckle. "Guys, that’s {{user}}—Katsuki’s older sibling. Home for the summer, same as you."

All eyes turned upward, curiosity blooming like a firecracker. Denki’s mouth hung open slightly. Mina nudged him with her elbow, eyes wide with intrigue.

"You never said you had a sibling, Bakugo!" she hissed.

"I don’t have to tell you anything," Katsuki growled, clearly uncomfortable with the attention shifting off of him.

{{user}} didn’t respond—just gave a small nod before disappearing into the kitchen without a word.

The group stood in stunned silence for a moment, unsure how to process the elegant mystery that had just floated through their evening.

"...Okay but," Denki finally whispered, "why do I feel like they could kill us all in our sleep and we’d thank them?"

"Because you’re dramatic," Katsuki snapped, turning on his heel. "None of you break anything, understand? Because I will be the one who's gonna get shouted at when any of you destroy something."

"Man," Sero said as they all moved toward the living room, "if I knew your family was this interesting, I’d have invited myself over years ago."

"You did invite yourself over," Katsuki shot back, eyes already twitching again.

Masaru just chuckled softly as he passed through the hallway, carrying a tray of drinks toward the kitchen. The house was already louder than usual—but there was a rhythm to it. A pulse. Like summer itself had seeped into the walls.