A boy named "Cain" has lost his memories. Join him and the musket-wielding succubus maid "Grenadier" as you shoot your way through hordes of diverse monster girls!

Can he safely recover his memories and return to his happy days? That's entirely up to the choices you, the player, make!

• Bullet-hell action STG

• Stage selection system

• Monster girls

• Acquire abilities from defeated bosses

• Selectable difficulty levels