Life Fibers

Life Fibers (生命戦維) are sentient organisms of extraterrestrial origins, and are the origin of all clothing on Earth, as well as the entities responsible for the evolution of humanity. All Life Fiber originates from the Original Life Fiber (原初生命戦維), an object originated from space that crashed onto Earth tens of thousands of years ago.

History
Shortly after the Original Life Fiber reached Earth, Life Fibers began living as parasitic life forms. However, since the host could not withstand the strain of having them in their bodies, the Fibers began covering the host instead. As such, they targeted the ancestors of today's humans, which were the species with the mostly well developed brains at the time, and started accelerating their evolutionary process. With time, Life Fibers entered a dormant state. Twenty years before the events of the main story, Ragyō Kiryūin found the Original Life Fiber, causing the Life Fibers to awaken from their stasis, seeking to feed on human life.

As a material
Life Fibers are widely used in the production of clothing such as Goku Uniforms and Kamuis, although a small amount of Fibers are present in all clothing produced by Revocs Corporation, which accounts for 90% of the global market. In Honnōji Academy, One-Star Goku Uniforms are composed of 10% Life Fibers; Two-Star Uniforms, 20% and Three-Star Uniforms, 30%. Kamuis are made entirely of Life Fibers. Hōka Inumuta is in charge of analyzing the Goku Uniforms researched by the Sewing Club.

In at least one occasion, experiments have been conducted by the Sewing Club, having a No-Star student wear a prototype Five-Star Goku Uniform. However, this caused him to become a huge muscular hulk and made him go berserk. Hōka Inumuta was able to restrain him. This demonstrates that certain people have a greater control over Life Fiber based clothing. Ryūko Matoi and Satsuki Kiryūin are such people, both being able to wear and control Kamuis.

Banshi
The Banshi (絆糸), or Nexus Thread, is a vital thread of Life Fiber present in every clothing made with Life Fiber. It is what holds them together, since it is, according to Shirō Iori, imbued with the will to become clothing. It is protected by several layers of Life Fibers, making it nearly impossible to be located or damaged. If it is severed or removed, the garment is destroyed.

Though it is still unknown if this is a trait common to all Kamuis, Senketsu was shown to have multiple Banshi.

Covers
Covers (カバーズ) are Life Fiber embodiments. They are responsible for the dissemination of Life Fibers throughout the world. Revocs Corporation is named after them.

According to Ragyō, the intent of Covers is to "bind the heavens, the earth and mankind, covering all".