I think Saotome has some kind of syndrome.
She feels indebted to Kuzuhana since she is the reason he can have "normal" school life. However, he seems not sure whether it is a romance or just some gratitude.
I can understand that. You feel gratitude for her but might fall in love with other...
wow this is indeed rare. They cold-headedly speak to each other and no miscommunication. This somehow satisfies me and not thinking "what if they know each other situation"
They might still fight each other but at least the reader does not need to feel agony of "PLEASE JUST TALK TO EACH OTHER...