I love this so much, and I have to ask if this is taking inspiration from a certain Quest involving Monster Girls? If so, then that's amazing cause I love that VN so much.
The art style is very adorable, the music selection is a bop (gotta love rengoku's work), the characters are interesting and quirky, the story has a cool premise, and I want to know more about what's going on, and the humor is so good and is right up my alley. This demo is hitting me with nostalgia in all the right ways, and I hope you keep on working on this cause I would love to see more. If there is inspiration taken from that VN then you are doing a fantastic job getting that vibe and feel of it incorporated in this.
Only main issue is that the English translation is rough, but I could still get the general idea of what's going on.
Wonderful work!