This game is amazing, and I can't believe it was made in RPG Maker. Only critique (serious one, the next is a huge opinion), I got so lost in your story and art there were small points where I was poking chairs until Oliver would sit and I didn't know you had a menu. It's small and nitpicky, but other than that the only fault I can give is (here it comes) if you are going to fill a city with cats, please make them able to receive pats!
I'm being serious when I say this is solid. (for the record, I only played part of it, but that's because I'm too busy to finish it right now) Anyway, the characters are interesting. Between the drawings you chose of them to use and what they say for embellishment (or getting to know them) they are able to carry the story to a point where I'm never slamming down the spacebar. I already liked the character that became the victim. Trying to do this without spoiling is hard, forgive me. I felt something when they died.
The story and the characters feel like they are one instead of two separate parts. That is extremely hard to do. I hope you can carry this talent through every visual novel you make, but stay humble and open to learning. (I don't like saying cheesy stuff like that usually, but I was arrogant when I was young and that was my biggest mistake) I cannot wait to see what else you can come up with. Thank you for making this game!