I'm torn between Melody and Scherza. I go all hanyaan for a well-executed clingy, childhood friend but Scherza was the more interesting character, with greater depth. I also liked that Scherza needed winning over, while Melody and Lyria were pretty much obsessed from start. It gave Scherza's narrative a little more suspense and momentum. It left you wondering 'if' rather than 'when'.
Lyria did little for me, sadly. I kept getting flashbacks to Ryoko from Tenchi Muyo. Not a bad thing in itself, but it was to the point where I struggled to separate the two characters in my head. It broke immersion something chronic, and it made me feel very old. She was maybe too playful and immature, or even too nice, to be a tasty sexual threat. Her boundary pushing felt less like a dominant woman seducing an ingenue, and more like a pushy teenager, grossly overestimating herself. There is charm in the latter, of course, but I'm unsure if it really tickles my fancy. Perhaps it would be the kind of thing that makes more sense with a shounen protagonist?
Still good work. I felt it rewarded multiple playthroughs. The plot and characters really benefited from exposure to their different aspects. I found the first run a little confusing and underwhelming, (I ended up lurching from Lyria to Melody, so it felt like half of one story, and half of another) but after exploring a little, everything made a lot more sense, and the emotional beats hit harder. Most visual novels I've played seem to do the opposite - everything just pales after the first run - but you've managed the opposite. I'd say that's an achievement.
Good luck with any future projects. I regret that Catch Canvas doesn't look like my bag, but I'll keep an eye out anyway. I'm open to persuasion.