Jump Ultimate Stars confusion!

1. Is it some form of power up when koma sparkles when added to the field?
2. How do I get extra points to upgrade my koma with outside of the story mode?
3. What does it mean when it says a demo was unlocked?

I remember DEMO unlocked is the scene of the manga that plays when you first enter a world. I haven't played in a long time and I honestly don't remember.