Delightful. Solved the mystery, but some bad rolls (I believe?) made me miss the clue in the flower shop, so I ended up with 90/100. Got the mystery correct on the first guess, though!
One thing I was impressed with: I am neither a theater nor a music person, personally, but the writing was accessible enough that it felt like my character was knowledgeable enough about high society theater and music to investigate the mystery even if I wasn't. There were a few terms, like the instrument names, that I ended up having to go back and remind myself which was which, but otherwise, I was able to follow along with those elements and their ramifications in the mystery despite not having the background. Well done on that.
The mystery itself felt like a good difficulty. It wasn't obvious, and the player has to pay attention to what the characters say, but the structure of how you made options for following up on specific items from interviews help the player to sift the wheat from the chaff in a way that makes it likely they will figure it out without the solution being handed to them. And the hypothesis system worked quite well as a way to establish a theory before making an accusation. Really nice mystery-solving design with some clever affordances to help the player succeed while still feeling like they're the ones solving the mystery.
I didn't read the game notes before playing, so I was a little surprised by the dating sim segment at the end. Once I realized what was going on, it was of course fine, but in the moment, it seemed odd because I expected the game to end when the mystery was solved and the perpetrators were brought to justice. In retrospect, it seems a lot more obvious that was what it was building up to, so this is probably more about my unfamiliarity with the conventions of dating sim games than any problem with the game itself. For example, I took the adjustments to the relationships as "willingness to divulge information relevant to the investigation or to step in if things go south with the villains", rather than "how into you they are". I now realize that was leading up to the dating portion, but when I was first playing the game, I thought those were investigation progress measures, not romantic measures. (A quick paragraph about what those bonuses mean might help orient people like me unfamiliar with dating sims, but honestly it's fine as is.)
Anyway, a solid offering. Engaging writing, a fun mystery, interesting characters, quick to play, easy to navigate, and no major frustrations. Great work.