One of the most interesting ways I see writers tackling their dynamic is by focusing on the silence. Most fics don't have them yelling or even talking much at first. It's all in the physicality—how Kyoutani might shove past Yahaba in a hallway but then linger, or how Yahaba's perfect serves keep targeting Kyoutani's side of the court during practice, not because it's a weak spot, but because it's a direct line of communication. They speak through competition, through the unspoken rules of the game, long before any words of affection appear.
A lot of stories use post-match exhaustion as a catalyst. The adrenaline's gone, the gym is empty, and they're the last two left cleaning up. That forced proximity without an audience strips away the performative rivalry. I've read a few where Yahaba tosses Kyoutani a water bottle without looking, and Kyoutani catches it, and that tiny, efficient motion holds more weight than a dozen love confessions. The rivalry becomes a shared language, a private understanding that no one else on the team is fluent in.
It's less about erasing their competitive edge and more about redirecting it. Their arguments over strategy or form evolve into debates over what movie to watch, but the same heated intensity remains. The best fics make you believe they'd still be at each other's throats on the court, but off it, that energy has just found a new, equally vital channel. You finish reading convinced they'd drive each other crazy in any universe, but maybe that's the point.