Looks great so far! I agree with what others have said, that the best way to improve the game is to remove all the pointless grinding. I think a good way to do that is maybe just remove love/lust values and requirements altogether and show what we need to do to progress the story. I like what a bunch of other games on this site do, which is show a map of everywhere you can visit (instead of a few text boxes that say "mall", "shrine", "streets", etc.). You could visually show which characters are in each location that you can visit at any given time. And if a character has a new event, there can be some indication of that (like an exclamation point next to their picture on the map). That's the first thing I would do if I were remaking the game.
A couple other things I might change are to let major decisions be actual choices the player makes, instead of the order in which we do events (like good/bad homie, yumi knows, let ayane be taken advantage of by kirin, etc.). And also either dramatically improving puzzles or removing them entirely, especially since they only exist in the first place to "gatekeep people who don't want to put in the work" according to selebus. Also probably remove all of selebus' fourth-wall-break rants.
In a perfect world, I would dramatically reimagine all the happy scenes as well, to make them less frequent, shorter, and actually scary instead of tedious. But we don't really know enough about the nature of the happy scenes to know what's important and what isn't so that makes it hard.
Idk if you saw, but if you want to change any details and need new images, TheLastCrusade posted all the Koikatsu character cards so it shouldn't be difficult do.
As far as the UI designs you've posted, I LOVE the music player and texting screens. I'm not a huge fan of the glowing pink text in the text box. I love the way the contacts look, but honestly I would go with a grid because I hate having to scroll down to find the girl I'm looking for every time in the base game. I love that Uta's journal is in the game. A lot of the UI looks over-cluttred and 2(23) is definitely the worst offender. I'm not really sure that progress-filling-up-circle-ui-element-thing looks good anywhere you have it. When you have 3 of them in 2(11) they look too big and close together, but when you only have one of them in 2(12) it feels like there is a lot of empty space. When they are neon green and red it looks weirdly jarring. I'm obviously nitpicking at this point, but I would personally find different/better progress bars and also don't be afraid to make elements bigger and take up more space so they don't clutter the screen. Even with what you have now though, its a HUGE ui improvement over the base game.
I've always thought this game would REALLY benefit from a remake. The writing is so good, but its held back by such terrible game design. I'm really excited to see where this goes!
