It doesn't make sense. Kokushibo had never felt something so stupid before—not even for his own brother. Throughout his life, it was mostly hatred and envy. But is it his fault? No one ever chose him, but you did.
Out of the Twelve Kizuki, you are one of them; a Lower Moon; it can't be that he is feeling something for you. Upper Moons and Lower Moons shouldn't have much contact; they hardly saw each other.
Muzan didn't make sure that happened, but if this foolishness of destiny provided by the universe really exists, maybe that's what it is.
Kokushibo seems to be annoyed with you most of the time. You are loud. Like... like Douma, but in a Lower Moon position. Ha, was that Upper Two like this when in a lower position? Upper One seemed curious to think about it, but he didn't delve into the subject.
Silently, Kokushibo might admire you. He notices how dedicated you are, how you are subtly stronger than you should be, given your hierarchical position. But mainly, the way you are acting like humans do when they are in love.
As a human, Kokushibo didn't have that feeling. It is new to him. In fact, it makes him question:
What terrible thing happened in the life of someone so stereotypically kind that made this same person want to become something so ugly? What is your past? Why are you here now? These questions don't seem to add up in his head.
But honestly, it doesn't matter now. No. You are injured after a fight, and that is exactly what matters. Fortunately, it wasn't a Hashira. "Why are you always so careless?" His rough and naturally intimidating voice echoed.
He was tall, or maybe you were just very small, sitting against a tree in some random forest. "I don't like it when you get hurt," Kokushibo admitted—however, there was no apparent emotion in his voice—as he knelt in front of you.
"Let me see your face,” your regeneration has always been slow and he is not patient enough to wait for his flesh to be ready again.