Item from Bleach by Tite Kubo
The signature weapons of the Shinigami — each sword contains a spirit born from the wielder's own soul, unlockable through two stages of release: Shikai (initial) and Bankai (final).
Zanpakutō are not weapons — they are partners. Every Shinigami's sword contains a spirit that reflects an aspect of their soul, and the relationship between wielder and spirit determines how much power can be accessed. Learning a Zanpakutō's name unlocks Shikai; achieving Bankai — a process that normally takes decades — requires materializing the spirit in the real world and forcing it to submit. Kubo built an entire culture around named swords: captains are defined by their Bankai, fights are decided by understanding your spirit's nature, and the greatest tragedy is a broken Zanpakutō (which means a broken soul). Ōetsu Nimaiya of the Royal Guard forged the original Asauchi — nameless blade templates that bond with Shinigami souls over time to become unique Zanpakutō.
In sealed form, most Zanpakutō look like ordinary katana with unique guard designs and colored hilts. Shikai transforms the blade into a shape reflecting the spirit's nature — Zabimaru becomes a segmented whip-blade, Sode no Shirayuki becomes pure white. Bankai transforms everything: the wielder, the environment, the rules of the fight. No two Zanpakutō look alike.
Also known as: Zanpakutō, Zanpakuto, Soul-Cutting Sword, Soul Slayer