This story's really interesting, and I'm excited to see where you go from here. The way the story is written feels like a fairy tale, and I really like that about it. Also, do you plan on having multiple "cases", or just the Moriya Shrine crew storyline? I think having several storylines for this idea would be cool.
I like the background and portraits, including the ones for Kanako and Suwako. To be totally honest, if you do a full-game version of this I'd prefer if Kanako and Suwako looked like that, just more detailed. The fact that these characters are literally portrayed as the animals they're themed around is really cute, and adds to the whimsical fable vibe.
Like MedalHunter said, it just sorta ends without anything getting resolved. Kinda sad, but I'll be there for the continuation if it ever comes out.