Karma

The Kizuna (絆) are metaphysical representations of the "ties" that connect people with other things in the world. They take the form of countless semi-physical strings (紐) that exist within and around all existences with shape. Through them, beings are connected to other beings, to inanimate objects, to nature itself, etc. Even the basic senses are the result of kizuna. They also apply to more conceptual connections, such as individuals to their family and ancestors, as well as to the needs of the world around them (thus creating the idea of "fate"/"destiny"). These connections are commonly divided into the positive and beneficial yang (陽), and the negative and corrupting yin (陰), corresponding with the same two types of energy present in the universe. The two naturally seek to balance each other, leading to the spontaneous creation of the Enmi in order to counter humanity and smaller, less consequential results. As a natural balance exists in the universe, so too are there supposed to be an equal amount of yin and yang kizuna.

The Red Strings of Fate that bind the human world to the Enmi world are 'artificial' kizuna, made by An'un (whose Supreme Ultimate state is composed of all the world's kizuna) in his study of the mysterious substance(s). The Modifires are often made with the stuff, and the resulting forms granted to the Riders are held together and empowered by them. Ari's contract with Saga no Mamoru and his descendents (as well as the seal that resulted) was also conducted through kizuna.

In addition to discovering and creating them, An'un can freely manipulate them. Kirie Monsan also gains a form of this ability while his apprentice.