A mysterious pyramid appears in Tokyo, and it may be part of a plan to sink Japan itself. Soon afterward, a woman named Emerald uses a strange ability to restore the wounded Yaiba to his full strength. Yaiba and his friends decide to enter the pyramid to uncover the truth, but deadly traps await them at every turn. Who is the shadowy mastermind behind it? No one knows, but a fierce battle is about to begin against a powerful and unknown enemy!
