Yeah, the issue with Tanya not being a main LI and not being a mandatory character is really bad.
My main issue is that the days are too empty, and that the MC just decides to watch TV or sleep through the entire day, you could add so many more character interaction every day, that would also help with the Tanya issue, and other characters that are just forgotten about for long periods of time and not even called, let alone mentioned until you add a new scene a week or more after their last interaction, the best solution is to cram more content and character interactions every in-game day, it really fixes so many issues, from characters not feeling forgotten anymore to him not feeling like a lazy bum who mostly sleeps and watches TV anymore, he'd even keep his promise that he'll always spent time with those he's with.
Another big issue is that there is barely any branching, what's the point of having so many LIs if they're completely disconnected from the story for the most part, if you're pursuing them they should interact more with other characters and the main story, and not just limited to their own locations/side stories, just to be forgotten for a couple week in-game, all characters you're pursuing should be intertwined in the main story, combine this fix with the other one and you have a solid game, I'm not opposed to a remake if it gets improved with these fixes, I know doing it like that means a lot more work and even more coding, and of course a way bigger game, but right now it's just hunting character scenes for the most part, when the biggest focus should be the story.
I know there is less than 1% chance it will be remade like this, but I still wanted to share this, no matter whether people and the dev agree or not.