After his high school graduation, Yuuki Wakura realizes it has been five years since his sister’s disappearance during a “Mato disaster.” Throughout Japan, mysterious entrances have opened to a dimension called “Mato”—a demonic metropolis filled with disastrous monsters known as the “Shuuki” that threaten the safety of humans. However, a new hope arose, as the discovery of a Mato fruit that grants supernatural abilities exclusively to women allowed them to fight against the Shuuki. Due to this, a new matriarchal government was formed, establishing a female organization called the Anti-Demon Corps, which caused men to fall to the bottom of society.

When Yuuki suddenly finds himself in Mato, he is unable to escape on his own. But just as he anticipates a gruesome end by the Shuuki, a girl in a militia outfit appears and protects him. Now in a life-or-death situation, Kyouka takes but in order to defeat the Shuukis nearby, he has to become her slave.