InuYasha and his companions learn from Gakusaijin that Naraku has stolen the Fuyouheki from him. He gives crystals of his demonic aura to Miroku to allow InuYasha's group to locate his stolen gem, thus finding Naraku. Kohaku encounters Kikyo, who is taken by surprise by Naraku, hiding his demonic aura with the Fuyouheki. InuYasha and his companions arrive just in time to drive off Naraku. The Fuyouheki was stolen because Naraku wanted to hide the demonic aura of his detached heart (The Infant), so Kikyo tells InuYasha that she must find the heart of Naraku to end this trouble. Hakudoshi creates an experimental series of soulless demons to attack InuYasha's group to steal the crystals from Miroku.