The Idols in School Idol Festival are categorized into three classes.
Smile- can be distinguished by the red background around the idol.
Cool - can be distinguished by the blue background around the idol.
Pure - can be distinguished by the green background around the idol.
The idols you can get in-game have abilities/skills that may help change the tide between getting a "B" and an "A" Rank on songs.
There are two types of abilities.
- Appeal - this is an ability that's triggered by certain conditions.
- Center Skill - this is a passive ability that differs depending on the idol.
Let's take for example Yazawa Nico she has "Rhythmical Charm" as an appeal.
her appeals conditions are:
For every 17 hit combo string, there is a 36% chance of increasing player's score by 200 points. (Level 1)
it's pretty self-explanatory.
As for her Center skill it's "Smile Power".
Increases Smile points by a bit.
This tells us that whenever Nico's is the center she gives us extra smile points to the total smile points.