Hi!
To be upfront, I'm not your target audience, so I didn't play enough to really rate the gameplay/the mystery. That being said, as a fellow dev, there are things that I can review without playing the full game :)
I really liked your UI, the menus were well thought off, the navigation was intuitive and it worked without any issues.
The audio was pleasant, the SFX well placed and diverse. It fitted well with the scenes.
It might be just a personal taste, but I found that the backgrounds didn't fit the characters well. I think using real images with a filter could have worked with characters with a different art style, but I think anime backgrounds would been better here.
I liked the writing, it can be hard to write dialogue and set an ambience, but you did it well.
Thanks for your submission and good luck with your game!