As fun as this manga is, basing starting a relationship on something like beating her in a game (or anything like that) seems... Disingenuous?
He's basically valuing his own pride over a relationship with the girl he claims he's in love with. It's selfish more than anything else, and not a good trait to bring into a relationship. While he's probably not prone to it, I believe it's one of the major causes for domestic abuse.
What happens after the confession, he just gonna drop the game or at least stop working on getting better at it?
Well, he's said he's going to continue playing with her.
This could all be solved if she does the first move, and I hope that happens just to undermine his efforts, that'd be great.
His efforts being undermined would be awesome, for above mentioned reasons.
I started it because it was by the same author of Takagi-san, but after reading 'SukiMegane' (which has the same kind of narrative tools, by the way) which is so genuine in their relationship representations and writing teens, one sort of... I dunno. Ignores it?
Yeah, SukiMegane is genuinely cute, and has a more reasonable reason for not confessing (and more commonly used, but there's a reason for that).
I started reading it because I saw it didn't have the same bullying aspect as Takagi-san, while hopefully sharing some of the better aspects. I gave up on that one because she was even worse than our selfish protagonist here.
The thing is, we don't actually no for certain what made him develop a crush or really all that much about Ayumu's time before this (aside from just Ayumu having previously done kendo).
It seemed to be some kind of love-at-first-sight kind of deal.
This is coming from someone who had picked up a new hobby and coincidentally run into someone who I had just known as "a funny friend-of-a-friend". We became friends and eventually both knew that we had feelings for each other but just left it at that for a while because best friends vs partners didn't make much of a difference. We both had goals that we were trying to achieve in that hobby (it wasn't in competition with each other) and only actually started dating after we had each accomplished those goals and were leaving that hobby behind.
That's definitely more healthy. Japan, or at least Japanese media, is very focused on the confession aspect. Where I live, and many other cultures, relationships are just what things grow into, without any fixed start. Not sure how it was for you, but making a conscious and mutual decision about it is far more mature.