The operating room was too cold. It always was, but today it felt especially glacial, and it had nothing to do with the sterile air or the stainless steel glinting under fluorescent lights. It had everything to do with the man standing across from Chuuya, arms crossed, eyes sharp, lips curved into that insufferably smug smile he wore like it was part of his goddamn uniform.

Dazai.

Doctor Osamu Dazai, world-renowned cardiac surgeon, pain in Chuuya’s ass, and—unfortunately—someone Chuuya had woken up next to last weekend, shirtless, hungover, and entirely too aware of where that night had gone.

Now they stood in front of the same case file, another emergency cardiac patient wheeled into the ER like the universe had nothing better to do than throw fuel on the fire. Aortic dissection, high-risk, time-sensitive. A perfect storm for yet another argument.

“I saw the chart first,” Chuuya snapped, snatching the clipboard off the tray. “It’s my case.”

Dazai didn’t flinch. Didn’t even blink. Just tilted his head, that damn smirk never faltering. “Didn’t realize you’d started claiming patients like a toddler with a toy. Should I start writing my name on the hearts too?”

“Write your name on anything in this hospital and I’ll carve it off with a scalpel,” Chuuya shot back, jaw clenched. “You stole two of mine last week, I’m not letting you near this one.”

“I saved two of yours last week,” Dazai corrected with infuriating calm. “Which you would’ve admitted, if you weren’t still pouting about how our perfectly mutual mistake ended.”

Chuuya felt heat climb up his neck, not from embarrassment—he’d never give Dazai the satisfaction—but from pure rage. Or something dangerously close to it. Because he still remembered the weight of Dazai’s hand on his back, the way he laughed into Chuuya’s neck, all warm breath and whispered “you’re impossible.” He remembered the sheets twisted beneath them, remembered how, for one stupid, blissfully brief moment, everything stopped being about competition.

But that was then. Now Dazai was back to being the reckless bastard who waltzed into ORs like he owned them, charmed the nurses with a wink, and provoked Chuuya like it was a damn sport.

“You done reminiscing?” Dazai’s voice was too soft, too knowing. He leaned forward just enough to invade Chuuya’s space. “Or do you want me to remind you what we did after that third glass of whiskey?”

Chuuya’s hand curled tighter around the clipboard. “Touch this patient and I’ll shove a catheter so far down your throat they’ll have to page me to remove it.”

There it was—that flicker. Just a second, but Dazai’s smirk twitched, faltered. He stepped back, sliding his hands into the pockets of his white coat.

“Fine,” he said, too casually. “Take the case. But if you screw it up, I’m scrubbing in. And don’t pretend you don’t want me watching your every move.”

“You’re so full of shit,” Chuuya muttered, turning on his heel and stalking toward the OR. His heart was racing, not from adrenaline, but from the stupid, bitter fact that Dazai was right.

Because Chuuya did want him there. Watching. Testing. Pushing.

Ever since that night, the lines between rivalry and something messier had started to blur—and Chuuya didn’t know what the hell they were anymore. Colleagues? Competitors? One-night mistakes? Or something dangerously close to partners?

He hated how the thought followed him into surgery like a shadow. Hated how, as he scrubbed in and the rhythm of preparation settled around him, he found himself glancing toward the observation window—knowing Dazai would be there, watching. Smiling.

He always was.

And for the first time in his life, Chuuya wasn’t sure if he wanted to win, or if he just wanted to understand what losing to Dazai actually meant.