Edit: TheCheat Engine File: https://mega.co.nz/#!p0R2iS5R!u1KcO6QSYrtnK2xuCtfhtTUXg2ktW2-JnxKHNb-YWfo
Couple of things:
-To play as this hidden character you must make the value for the code that says "Character Selector" 11. Then, you must go into advanced options, right click on the entry in the box and select "Replace with code that does nothing." She may or may not appear in the character selector box, but rest assured, you'll be playing as her once the game starts.
-The auto recover and groundbreak killers only work for Cocoa, Nagi, Itsuki, and the mystery girl. Be warned that for both the CPU and player, playing as these characters becomes harder, because all possible recovery is now left up to button mashing.