While two were left to his sons, their father had sealed a third sword, Sounga, away so that its powers would not harm the world. Things turn really bad when Sounga breaks free from the seal. It only had a thing on its mind: to destroy the other two swords, the only two weapons capable of defeating it. Sounga seeks out someone to wield it so that it could end the dog demon blood line. Could Inuyasha and Sesshoumaru set aside their years of squabble aside long enough to defeat Sounga, or will they all perish?