Innocent Style:
After getting Hermana in your party, get at least three styles to level 15. Then, sleep at an Inn to unlock Innocent Style.
Versus Style:
-Select Wi-Fi mode and sleep at an Inn. Save the game to unlock Versus Style.
-Alternately, unlock all six characters and defeat an enemy in under one second. Then, sleep in an inn. You will unlock Versus style for all characters.