并称为“天下霸道三剑”的天生牙、丛云牙和铁碎牙分管天、地、人三界,当年全部为犬夜叉的父亲斗牙王所拥有。斗牙王与人类公主十六夜相恋,生下犬夜叉,此举惹来暗恋十六夜的武将刹那猛丸的嫉妒。身负重伤的斗牙王用天生牙救活被猛丸杀死的爱人,随即与猛丸展开决战。恶战之后,斗牙王生命将终,他命冥加将天生牙和铁碎牙分别赐予杀生丸和犬夜叉,而拥有邪恶强大力量的丛云牙则被永久封印。 数百年后,丛云牙通过食骨井来到现代,并摆脱了封印的束缚。它先控制犬夜叉的身心,回到战国时代与杀生丸展开一番恶战。危难之际,戈薇的力量使丛云牙被迫离开犬夜叉的身体。但它很快又找到新的替身,并且将已化作白骨的刹那猛丸重新召唤回人间,向斗牙王的两个儿子展开报复……The legendary sword, So'unga, which belonged to the Great Dog Demon, has been unleashed. It seeks to cover the Earth in an eternal Hell and end all life on it. Inuyasha must join forces with his hateful brother, Sesshoumaru, and put an end to the evil sword that once belonged to their father.