Yuto Takamine and his younger sister‑in‑law, Kaori, are visiting their parents’ graves when they are suddenly summoned to the other world of Phantasmagoria. There, the king and a woman named Restina capture Kaori as a hostage and demand that Yuto fight their enemies. The king then gives Yuto a sword called Motomeh, which he must wield to defend the kingdom from hostile spirits. Kaori will be released only if Yuto fulfills this mission, and so Yuto's journey begins.