Kinzō Hattori leads a ninja clan in Japan's Shinobi Village. He shares a long-standing friendship with Master Splinter, forged during their past training together. When supernatural threats endanger his clan and compromise sacred artifacts under their protection, Hattori contacts Splinter for aid. This summons Splinter, April O'Neil, and the Ninja Turtles to Japan.

Hattori's clan safeguards the primary artifact, the Mi-Yuu-Tai-Shi, a magic mirror embedded with seven Mutastones (also called Magatama). These stones embody celestial and elemental forces: the sun, moon, and five classical elements, granting transformative abilities.

During the ensuing conflict, Shredder, Bebop, and Rocksteady infiltrate Shinobi Village to steal the Mutastones. To protect the mirror, Hattori activates a defensive mechanism, causing the clan's castle to elevate dramatically and positioning the mirror atop its heightened structure. This forces his ninja forces and the invaders alike to ascend the castle to reach the artifacts.

Hattori possesses crucial knowledge of the Mutastones' limitations, revealing that the Metal Mutation transformation they grant lasts only six minutes. This proves strategically vital in the battle, as Shredder's group activates their transformations earlier than the Turtles, placing them at a temporal disadvantage.

Hattori's role focuses on coordinating the defense of the Mutastones and providing critical information to Splinter and the Turtles during their confrontation with Shredder.