The gun of the artillery lady is about to roar into another world! Two sisters who dream of becoming soldiers rush out into the night with a cannon. Elizabeth was born and raised as the heir to the kingdom's arms dealer, and due to an unexpected turn of events, she decided to follow the path of a soldier.However, she was repeatedly refused entry into the army, and her father decided she had no intention of taking over the family business, and eventually disowned her.As a last resort, Elizabeth decided to run away from home to become a soldier together with her sister Ellen.At that moment, they smelled something burning and saw cavalry approaching them...