Wow there is a LOT of characters in this game. I was going through the introduction portion and was just hoping there wasn't going to be a test later because I didn't remember half of their names. :D
If I were going to tackle it I might introduce the player in the audition process and give a few key characters in a tutorial, then pair up other characters into "teams" constructed of archetypes of personality that can be drilled into for more nuance. As it is the introductions are just to much to take in for me.
The artwork is great, I like the way that the game animates the portraits with the emotions. It's a really great system for visual novels. Overall really nice work!