Onoe manages to be so straightforward despite his own confusion and his own feelings and his own heart beating out of his chest and the way he ends up insulting him because Kaburagi just doesn't express himself the same way. (It's the same reason Onoe is the absolute worst at being paparazzi, he's so straightforward and so willing to trust and to believe in people.) But it's also why Kaburagi likes him so much, that inherent kindness that tempers his straightforwardness, the gentleness he has untempered by the world they both live in and report on.
But then getting the realization at the very end, Onoe slowly piecing together the full picture that Kaburagi won't speak but will act on. The way actions sometimes have to speak louder than words but you have to be willing to listen to them. Because part of their problem is that Kaburagi lives in the world of paparazzi much more than Onoe does, he lives in a world where he can be superficially affectionate with everyone equally and showing that someone means more takes the little things he won't give anyone, buying their favorite yogurt or looking out for them in moments he wouldn't for anyone else.
Onoe wants the big confession and to move on but Kaburagi builds a relationship in the little moments and gestures. He is not straightforward as Onoe is, he is not one to speak clearly and from the heart when he can take a step back, turn it into a tease or a more subtle comment.
This is a relationship that's got a lot about learning to speak another person's language, not just in love but in general. How do someone who is straightforward and shy communicate with someone who is neither? How does someone who is used to codes and subtle touches communicate with someone who needs to be hit with a truck
