Visuals: Fine enough as far as a rough draft goes. The character designs are good, though not exactly my cup of tea. If I wanted to choose a favorite I guess it would be Clover, since I can relate with constant eye bags. Only feedback would be that I prefer VNs that have the characters from the waist up(zoomed in), though I know that's more a case of personal preference. If you plan on still displaying the whole character sprite, it may be worth while to implement 'NVL' mode so the player can see it all without having to hide the text box.
Setting: As a fellow Christian, having a narrative with it as the primary backdrop is refreshing compared to the norm, though I imagine it will put some people off. Being a Protestant, I didn't follow some of the Catholic specifics, but I think you described it well enough that I could follow along. Intro was ok enough, though it feels a bit unrealistic. Maybe I just had a good High School, but I never saw physical sexual harassment ever. It also seems extra weird they would touch her in a public space near school with witnesses. As for the lore of how monster people came about, it's kinda iffy. I know it isn't the focus of the story to make it make sense, but how monster people came to be can affect the current story. One major question is of their culture. Do they have some antient culture, language, and traditions unique to them? Also the Catholic church's proclamation may have had dire effects, like another church-schism scenario if some people were calling them demons.
Story: I don't read many VNs, and the genre I like the least has to be dating/slice of life. So as far as how good this is for its genre, I can't say. It looks like the game will primarily be about relationships, whether that be with monster girls or Christ, which I find mildly amusing. The prose was serviceable, with a few typos/confusion from poor wording(or poor reading comprehension...). Characters were decent, though it feels like they're still more of archetypes than characters. Some media references like v-tubers feels cringe, but I suppose it is a thing that students would talk about now a days.
Miscellaneous: Was that a Higurashi reference after exiting the cathedral for the first time? The way the night sky looks spooky plus the phrasing felt like a homage almost.
Overall: It's decent all around besides some autistic gripes I have, for a rough draft. Christianity being so prevalent will definitely be a make or break for a bunch of people, as you probably recognize. While I'm not very invested due to my distaste for the genre, I wish you luck on making the VN.