Reformation

Reformation is the process where a girl becomes corrected and is no longer a criminal. Her outfit and voice lines change, stats and cost are altered, and the last line of Punishments are unlocked.

Requirements

 * 1) At least Level 50
 * 2) Viewed all 4 Diary Entries

Diary Entries
Every girl has a backstory that can be explored on certain levels of a certain Labyrinth. An event is unlocked on a certain level when her affection level increases. The decisions you make in the Diary Event don't matter, it only matters that you've viewed them. The final diary entry seems to be only found in B20 of the Labyrinth corresponding to the girl's sin, so at the moment only Anger, Lust, Greed, and Gluttony girls can be reformed.

Experience
The amount of experience required to level up remains the same for a certain interval. Higher rarity girls require more EXP to level up.
 * Common: Same as Base EXP
 * Uncommon: 110% Base EXP
 * Rare: 120% Base EXP
 * High Rare: 130% Base EXP
 * Super Rare: 140% Base EXP