From the Manual:
Yuko! Valis Warrior!
Long ago, in the ancient Land of Vecanti, a kind and generous King ruled the countryside. But alas, one day the mighty King Rogress died. As the people of Vecanti mourned his death, the country fell into a state of war and despair.
An evil army, headed by the Emperor Magus, has all but defeated the followers of the dead King Rodress. Rising to the occasion, for the first time ever a young woman named Yuko is chosen to become a Valis warrior.
With a keen mind and strong body, Yuko has something the Evil Emperor Magus fears - the legendary Sword of the Kingdom, Valis II. With heroic strength and the power of this magical weapon, Yuko sets out to destroy Magus and his savage army. She is aided by a friendly ghost, Reiko. But beware, Yuko. Magus has sworn an oath that he will take your life and become the new King of Vecanti. The fate of the Kingdom is in your hands!
Object of the Game
Defeat the evil army and bring peace to Vecanti. Use the magic of Valis II, power-up items and other weapons to your advantage. Score as many points as possible during the course of the game.