This story shares the tale of a young boy whose father was killed during a post-war conquest in a world called post-apocalyptic world named Ganeiya; where magic exists. The young boy goes by the name Iwata Naoki. He lives on with his father's sword in his possession and plans to return justice to the forsaken world. However, he faces many problems when he advances deeper into the life of nonstop fighting. With these encounters, he challenges both his mental, physical, and mana limit and grows stronger. He forms a group of warriors who work together with him to end everything and satisfy their goal.