One way to increase CP in the Campus Play game is by upgrading the grade of your belle. To upgrade belle, an item called Crystal Rose is required. The crystal rose is a rose shaped but with a crystal blue color.
How to get a crystal rose
- Story.
- Rooftop tournament.
- Rooftop store. 800 points to buy 3 roses.
- Patrol
- Belle random trip. The prizes are random, including rose.