Fuyōheki

The Fuyōheki is a magical item from the InuYasha manga series. Originally in the possession of Gakusanjin, it is a stone that masks the presence of yōki (yōkai energy). Naraku stole it in order to mask the demonic aura of Akago, who is his heart. InuYasha, Kagome, Miroku, Sango, and Shippo came across Gakusanjin, who was angry and uncooperative at first, but after Inuyasha asked whether Gakusanjin was conspiring with Naraku or not, he calmed down slightly. Also, Inuyasha had the opportunity to slay Gakusanjin with the Tessaiga but chose not to out of respect, which is what made Gakusanjin trust Inuyasha and friends.

During the encounter, Gakusanjin told the team that the Fuyōheki dissipated demon auras, and allowed him to remain in a slumber. Gakusanjin never completely trusted them, but gave them crystals that contained his own demonic aura. He told them that the crystals were green when surrounded by their demonic aura, but would look like pure white crystals in the presence of the Fuyōheki.

Once, the crystals turned white because they were near the cave in which Kanna was hiding Akago and the Fuyōheki. Kagura came upon them and attempted to kill Akago, but failed, as Kanna took the infant into her own hands and ran off the cliff on which the cave existed.

It was later absorbed (along with Akago himself) by Mōryōmaru. After the destruction of Mōryōmaru, in a failed attempt to destroy Naraku, Miroku sucked it into his Kazaana.

Fuyōheki is translated as "seal (fu) enchanted (yō) stone (seki or heki)" or "the demon-sealing stone".