OH MY GOD
Everyone thinks Kuroo loves cats so they always let him cat-sit for them and hang out with their cats, and he does love cats, he DOES, there’s just the little problem of the crippling sneezing fits he’s subjected to whenever he gets within five feet of one… Also, this probably goes without saying, but cats really love Kuroo and every time they see him they jump up on him and try to cuddle him into oblivion. He’s overjoyed and will keep cuddling them even though to the outside observer he looks like he’s literally about to die from his throat closing up. The cats are too important.
Kenma’s probably the only one who knows he’s actually allergic because he’s spent too much time with his throat almost completely closed up around Kenma’s cats to be able to fool Kenma about it. “No *achoo* way, *wheeze*, Kenma! I’m *achoo* totally fine!” Yeah right, Kuroo.
Kenma keeps allergy medicine around for him now because he knows that nothing is stronger than Kuroo’s drive to pet cute small animals, so it’s up to him to make sure Kuroo doesn’t sacrifice his health in his quest for cute.