Arata is a young man from a noble family in Amawakuni who has always been expected to make life his own until news arrives that the princess is growing weak. His grandmother had claimed him female at birth and, with no other females available to succeed the princess from the matriarchal Hime clan, Arata finds himself next in line for the throne. Disguised as a woman waiting for a replacement to be found, he witnesses an assassination attempt on the princess by her own guard, the 12 Shinsho. The crime is pinned on him, forcing Arata to flee to the Kando forest where it's said no one escapes unchanged.
In modern-day Japan, Arata Hinohara yearns for an escape from his cruel classmates. While walking down an alleyway, he accidentally switches universes with Arata from Amawakuni. With his newfound powers as a "Sho" - a warrior capable of wielding Hayagami, weapons imbued with the power of gods - and the help of his companions, Hinohara sets out to restore order in this new world.