D'Artagnan is just a regular country girl living alone with her father. Life is poor but peaceful. Yet nothing peaceful lasts. Her home is invaded by monsters and her father died under their attack. D'Artagnan only survived because a red eyed swordsman stepped in in time to save her.
To ensure that she never falls victim and to find the culprit behind the monsters, she enrolled into Chevalier Academy to become a musketeer.