Before Inuyasha and Sesshomaru's father, a great dog demon, died he possessed three swords: Tessaiga, the sword of the mortal world, Tenseiga, the sword of heaven, and Sounga, the sword of the...

Before Inuyasha and Sesshomaru's father, a great dog demon, died he possessed three swords: Tessaiga, the sword of the mortal world, Tenseiga, the sword of heaven, and Sounga, the sword of the underworld. After his death, the Tetsusaiga was hidden in his grave for Inuyasha to retrieve when the time was right, and the Tenseiga was given to Sesshomaru. The third sword, So'unga, was then sealed in the Bone Eaters Well where Kagome's family gained possession of it. Now So'unga has been released from its seal and fallen into Inuyasha's hands. The only problem is that the sword has a mind of its own and has taken control of Inuyasha. Now Kagome and the others have to stop Inuyasha before So'unga makes him do something terrible. But that is only the beginning.