Goku Uniforms (極制服 Goku Seifuku ), sometimes translated as Ultima Uniforms, are uniforms worn by high rank students at Honnōji Academy. Created by the Sewing Club, Goku Uniforms provide their wearer with incredible superhuman powers. The strength and abilities of a uniform varies by the percentage of Life Fibers it is made from, represented by the number of star-shaped markings emblazoned on them. Satsuki Kiryūin administers uniforms to students based on their skills and capabilities, which also determines their rank within the school hierarchy.
Goku Uniforms go from One-Star to Three-Star, with Five-Star uniforms being created for testing purposes by the Sewing Club. No-Star (無星 Muboshi ) students do not have the right to wear Goku Uniforms; they wear regular uniforms instead.
Goku Uniforms are extremely tough, but are not indestructible. Weapons such as the Scissor Blade and Tsumugu Kinagase's arsenal can damage or weaken them. Pulling out their Banshi will instantly destroy them, but this is a nearly impossible feat to achieve. According to Nui Harime, the Goku Uniforms have 'weak stitching' and are, in her eyes, 'crude', implying that they are nothing compared to her work. Goku Uniforms can also be worn out due to excessive use and will deform and disintegrate. Sanageyama demonstrated this during his battle against COVERS, where his uniform was destroyed due to overuse.
One-Star Goku Uniform
One-Star (一つ星 Hitotsuboshi ) uniforms are the most common variety of Goku Uniform, comprised of 10% Life Fiber. They are light gray gakuran uniforms with a single large four-pointed star symbol emblazoned on the center of the jacket, and a smaller white star on its collar.
Two-Star Goku Uniform
Two-Star (二つ星 Futatsuboshi ) uniforms are made of 20% Life Fiber and are exclusive for club presidents, though being a president does not require the student to be a Two-Star. Their appearance and application varies greatly, with the main distinction of these uniforms being the reddish lining over many surfaces, sometimes over some parts of the uniform, and always over the Uniform's stars and manifested weaponry.
Three-Star Goku Uniform
Three-Star (三つ星 Mittsuboshi ) uniforms are the highest-ranking Goku Uniform, made from 30% Life Fiber. The Three-Star Uniforms are worn exclusively by the Student Council's Elite Four and Shirō Iori. Each uniform's design and abilities are uniquely attributed to its wearer's default capabilities. Their colors range from pure white to light blue, and typically possess spikes and razor edges around the shoulders, sleeves, and/or unique accessories. When worn, they make their users completely immune to attacks from One-Star and Two-Star uniforms. They are also able to transform in a similar manner to Kamuis and grant the users overwhelming and unique powers.
Five-Star Goku Uniform
Five-Star (五つ星 Itsutsuboshi ) uniforms have been created at least once for testing purposes by the Sewing Club. These uniforms, composed of 50% Life Fiber, have been shown in at least one occasion to grant incredible physical strength and muscle mass gain to regular students, though causing them to go berserk.