I've been thinking this lately. Who do you think expresses their feelings more? Onodera or...

Misaki does.

I think it's misaki

Misaki does; but I think it's truly because of a difference in experience and age. Onodera, at Misaki's age, was far more open and in-tune with his emotions, but as we all know, when being honest didn't do anything but get him hurt, he easily fell out of alignment with himself and put up a jaded facade.

Misaki, as a character, has always had a lot of luck and success with being honest about things. This is really because, in my opinion, he largely deals with very experienced adults who find his sort of brazen zeal refreshing. But there hasn't been an instance yet where his being honest has majorly backfired in a way that ends up (rightfully) irritating or hurting another person(there is Misaki's "tragic" backstory, but that seemed to do little harm in the way of his ability to communicate with others, in fact I think it made him more sensitive).

All in all, I think Onodera and Misaki are very different people: whereas Misaki expresses himself more, outwardly, he is very willful and peripheral about his observations. That is, he's a very 1-to-1 sort of boy, who says what he thinks and thinks what he says. Onodera on the other hand might UNDERSTAND things with more complexity, and in fact, he probably considers his own personal situations and career with more delicacy, but perhaps because of this heightened state of purpose, he isn't very quick to voice himself - this is especially, as I said, considering he is a working man who is not in a position of authority, and for whom is trying his best to escape the "natural" authority of his company inheritance.

Misaki in my opinion.

Wow!! I like the way how you think or how you thought of things. It was very deep then. ^_^ At some point, I kinda agree with you.