Tokyo―the capital of Japan.
A mysterious man named Phantom plots to regain his sealed powers.
By giving weaponry known as F.A.s (Fu-mension Artifacts) to the young with special abilities, he lures them into battle with the promise of granting the victor their wish.
However, unbeknownst to the participants, the violent clashes of F.A.s cause distortions in the fabric of space-time, creating rifts between this world and other parallel worlds―rifts that will ultimately compromise the seals binding Phantom's powers.
Waka, daughter of the Kumon Family―an ancient clan that has waged war against evils―along with the support of Mikoto, fights to thwart Phantom's evil plan, but despite their combined might, Phantom manages to escape just in time. While fleeing, he kidnaps Waka's younger sister, Nagi Kumon.
Itsuki, a maid and self-proclaimed Arbiter of Justice and Yuzuha, a ninja who has resisted Phantom's temptations, join forces with Waka and Mikoto to pursue Phantom and rescue Nagi.
