Nanao's "zanpakutō" is , a family heirloom used in the Ise clan's rites and rituals. Unlike other Soul Reapers, members of the Ise clan lack "zanpakutō" and only the family head can inherit Shinken Hakkyōken. Nanao is rarely seen with the weapon for most of the story until Shunsui's battle with Lille Barro, her superior having sealed the "zanpakutō" into Kyōkotsu to honor his sister-in-law's wish to hide the apparent source of the Ise clan's curse from Nanao in hopes it would end with her generation. But as a last resort, as Shinken Hakkyōken is able to harm divine beings, Shunsui gives the bandaged "zanpakutō" to Nanao while she accepts the consequences despite being skeptical of it. In its Shikai state, Shinken Hakkyōken takes the form of an ornate medium-sized bladeless sword with a flat end with ability to take the power of a god into itself and disperse it off into the eight directions. The weapon did appear in the art book "All Colour but the Black" in its basic unwrapped form, appearing as either a "wakizashi" or a "tantō".