In a village of ninjas, an ancient prophecy foretells that a "Western Hero" will one day arrive to save them from the demons that plague the land. When the Demon King attacks, the promised hero appears and repels him, then entrusts a young ninja with a sacred scroll — naming him the Messenger and charging him to carry it east, to the top of a distant mountain. Aided along the way by a mysterious blue-robed shopkeeper, the Messenger sets out across a perilous world, his simple delivery gradually drawing him into a far greater struggle that spans centuries and bends time itself.