AP, also known as Ability Points, is a stat that allows characters' abilities to be mastered. Every time you win a battle, the character gains a certain amount of AP which fills up the "AP bar" found on each equipped ability. Getting enough AP to completely fill the AP bar causes that ability to be Mastered. When an ability is mastered it occupies less CP and may sometimes even unlock new and more powerful abilities. There are certain items, equipment and accessories that increase the amount of AP you gain after each victorious battle, most especially the effects of the Calendar.