A lot of people saying they don’t like each other or they should just get married now are missing the point. The story’s 23 chapters in so it should be pretty apparent what its themes are by now as well as the mindsets of its characters.
He’s the kind of person who can go a month without talking to someone and she’s the kind of person who needs to talk daily. Yes they’re opposites, but it’s because they’re opposites that they can even have this friendship.
Rihito would be unlikely to have any deep human connections if it were left to him to make the initiative, and Noa is the type who gets used and discarded or who annoys people with how clingy she is. He needs her because she’s able to break through how anti-social he is and she needs him because he’s the only person who could ever be so calm and patient when dealing with her. There have been a lot of moments both implied and explicitly stated where Rihito finds himself enjoying Noa’s company and where Noa is trying not to completely treat Rihito as her emotional support crutch like she did past relationships.
Whether as friends or more, their opposite personalities were written to complement each other.
PS: If you want a real life example of this sort of opposites attract friendship, just see streamers Cdawg and Ironmouse.