Annoying not as doting but as in obsessed and very one sided. He's not his older brother. He insists upon his opinion when nobu clearly said no and he doesn't want to go to that dinner while using his relationship to force him the schedule regardless on an adult. I'm an older sibling too I never force my will on my sibling no matter how much I think it's best for them
Nobu has to go to that dinner if he doesn't want to end up being forced to take over the company. Riichi knows that Nobu has his own plans for his future and he needs to discuss that with his parents regardless of how uncomfortable they make him.
Riichi is pestering Nobu but he's doing it for him. I actually dont even think that Mario realizes this.
I think Mario and Riichi are a great team and handled it well. Riichi worries about Nobu's futur and makes plans to ensure that Nobu can do what he wants, and Mario brings it to Nobu in a way that he can understand. They both care for him in their own way.
Which that dinner got cancelled pathetically and just ruined everything. At the end of the day its between their family and nobu is an adult. Pestering him around a person of just because of their sake is wrong. He doesn't have boundaries and wanted to try using Mario's feeling to still make something that clearly being forced here work. Anyway that's why I said probably an unpopular opinion so I don't really care people agree with me about it
He's been with him almost his whole life, and all three of them value each other equally. Blood relations be damned. They each have their flaws and annoy each other. That's just how human relationships are. It's okay to just not like him, of course. I'm just saying that it makes sense canon-wise, because the MC has always been hard-headed, meddling, single-minded, and obsessive towards those he loves. They've all been meddling and pushing their wants onto each other this whole time tho fr

Unpopular opinion but riichi is annoying about nobu. I prefer how mario act towards him instead.