InuYasha's group rescues a swordsmith named Toshu from the demon Ryujin, who is angered that Toshu has not completed crafting Dakki, a sword designed to absorb other's demonic energy. Toshu later uses the sword to absorb Ryujin's power, then battles InuYasha and steals the demonic energy from Tetsusaiga. However, the demonic energy is too powerful and kills him. The energy of the sword returns to Tetsusaiga, giving it the ability to absorb demonic energy. Meanwhile, a wolf-demon named Kai tricks Koga into helping him, seeking a Shikon Jewel shard to rescue his younger brother from the demon Byakuya, one of Naraku's incarnations.