I don't know about LN or stuff like that and also the fact that it has the romance tag, but i do think there's a possibility that this manga never goes full romance between them, like i could see a last chapter where they just drink together as friends
Considering the fact she is so obviously into him, I dont think its gonna end that way.
All her faves are copies of Rihito, hates the idea of him having a gf, was happy to hear he has no experience, is super clingy to him specifically, always wants to get closer and learn more about him, now she wants head pats and hugs. I mean the list is endless.
Rihito's list towards Noa is much shorter but like his lil sis summed up "hes always liked interesting people" well who else is more interesting than Noa. She adds mad amounts of color and energy to his life.