Long time ago, there was a war between the Evil God and the Dragon God. However. The war was settled when a dragon ninja, who had the power of the Dragon God, sealed the Evil God.
Several thousand years after, in New York, a young ninja mamed Ryu is attacked by a couple of men in black suits wearing white masks. He notices that they are related to someone worshiping the Evil God, and he resolves he should have to fight against them again before the Evil God is unsealed again.