Akutsu Takuma, who earned the nickname Devil for his frightening face, has long been accustomed to loneliness and is not troubled by it; he devotes all his energy to studying in order to fulfill the hopes of his late mother. But the quiet days of the boy come to an end with the arrival in his life of the girls Saotome, young Valkyries. They call Takuma Odin and declare that together they must save the world from a demon invasion and total destruction. The power of the Valkyries emanates from love, and Takuma must grow close to the girls in order to save the world.
