Thanks for checking it out!
I agree, the ATB system is not great. In all honesty, I really don't like RPG Maker MZ's default ATB system - it seems tacked on and incomplete, and is super finicky and hard to modify. I only used it because it was the only way to get the party-member position-switch mechanic to behave properly. Luckily, I think I've found a way around that, so the next version of the game will have a more conventional Turn-Based combat system.
Mr. Nagawa's explanations are total gibberish and have pretty much nothing to do with math! I think there's a line where he says something about a number being "past tense", having a participle, and being conjugated (that's grammar stuff lol), and he references "Fergnatz's Last Theorim", which is a mispelled nonsense version of some math thing I heard about once. The scene is total nonsense and was fun to write, and honestly, it's what normal math explanations sound like to me anyway lol.
I like the idea of a time-of-day on the HUD and may work it in. The game is getting a "Night Time" phase soon, which gives Chiyoko more options for training and patroling the city, so it would make sense to add it.