As the kingdom of Highland and Jowston City-State are about to sign a peace treaty to end their long-lasting war, a massacre occurred at the camp of Highland's army of young men called the Unicorn Brigade with Tao and Jowy as the only survivors. They discover that the one behind this was the Highland prince, Luca Blight, and now, they were branded traitors of their own country.

Rampaging Luca Blight only brought destruction and death of the innocent ones, leading Tao and Jowy to take upon each halves of the Runes of Beginning, one of the 27 True Runes that created the world, Bright Shield and Black Sword respectively. As a shield that continues to protect, Tao walks upon the journey of protecting the smiles of those who are important to him, even as he faces the inevitable fate he and Jowy have to go through as the bearers of the Runes of Beginning.

Based on the PSOne video game, it is also loosely based on the Water Margin classics, though it's limited only to the gathering of 108 Stars of Destiny in order to restore order.