Because of the mistaken belief that a virus had eradicated all life in Ootsuka, the village was set ablaze and Shino Inuzuka, Sousuke Inukawa, and Hamaji were faced with their imminent demise. It was a stranger wielding a sword who appeared before them, offering them a choice that would determine their fate. That one night would forever change the course of these three youngsters' lives. For five years, their new home in a neighboring village shielded them from any prying eyes. However, the Imperial Church suddenly took an interest in the family of three, specifically the Murasame sword, a weapon of evil. Their plan involved kidnapping Shino's sister, Hamaji, and waiting for Shino, the rightful owner of Murasame's soul, and Sousuke, who could assume canine form, to undertake a risky rescue mission. The brothers overcame their differences to rescue their beloved sibling from the grips of the Church in the Imperial Capital, embarking on a monumental journey that was just beginning.