Sakon and Ukon

The brothers mirror one another: fair skin, straight dark-blue hair, and long bangs that conceal one eye apiece, Ukon's falling left and Sakon's right. Green lipstick and dark rings around their eyes lend them an androgynous cast, and a cursed seal sits hidden above the eye of each. Their matching outfits pair brown tunics bearing the Sound Four crest with black shorts, arm-warmers, and a rope-like sash knotted at the waist; Sakon adds a red beaded necklace and a large scroll so the two can be told apart. Because Ukon tends to slumber inside his brother's body, his head can be seen lolling from Sakon's upper back. When their cursed seals reach the second stage they turn oni-like, skin reddened, horns sprouting, and hardened black plating spreading like armour across their limbs.

Sakon was spiteful and cocksure, a fighter who savoured dragging out a bout and mocking whoever he faced, a habit that often slowed the group down. Rated the fastest and strongest of the Sound Four, he took great pride in the distinction. Ukon shared that confidence but ran a shorter fuse, his impatience offsetting his brother's love of stalling. The twins trusted each other deeply yet could appraise one another coldly in combat, and Sakon, though usually the more active body, deferred to Ukon's authority. After being resurrected in the anime, both nursed a bitter fury over their deaths and threw themselves at killing the team responsible.

Sakon and Ukon first surfaced with the rest of the Sound Four, raising a barrier so no one could interfere while Orochimaru fought and killed the Third Hokage. Sent afterward to bring Sasuke Uchiha to their master, they wore him down, dosed him to advance his cursed seal, and boxed him up for transport. When the Sasuke Recovery Team caught up, the twins split from the group to take on Kiba Inuzuka and Akamaru, unveiling the kekkei genkai that lets them merge and part at will. Ukon could dissolve into an enemy's body and wreck it from within, though he suffered whatever wounds he inflicted, and together the pair could raise the iron Rashomon gate for defence. The chase ended when Kankuro trapped them with his puppets, running both brothers through with his Black Secret Technique. Later, in the anime, Kabuto Yakushi reincarnated the twins to fight in the Fourth Shinobi World War, where they clashed with Kiba once more before their souls were finally released to the afterlife.