Sekirei

Sekirei (鶺鴒?) are superpowered beings with a different code similar to a human's. The Sekirei spaceship crashed on Earth in 1999 on Kamikura Island (神座島, Kamikura-jima?), and was found by two students, Hiroto Minaka (future MBI chairman) and Takami Sahashi (future MBI head researcher and Minato's mother). On board, the pair had found 108 life-forms, described as "One pillar and 107 baby birds".

• The first of them (a pillar, shown as #00, later renumbered and known as #01 Miya) was an adult.
• Eight (later known as #02-09) were embryos, also known as the "Single Numbers".
• 99 others (later known as #10-108) were fertilized eggs.

The adult and the eight embryos are also known as the "Single Numbers". It is hinted that unwinged Single Numbers are equal or even more powerful than their winged counterparts. All of the Sekirei had used adjustments for the Sekirei Plan, especially the Single Numbers. The adjustments had been used not only for making Sekirei stronger, but also for controlling and strengthening their power. Each Sekirei has a Norito (祝詞?, lit. "Incantations"), a unique ability that allows them to perform powerful attacks. In order to use the Norito, a Sekirei must be grabbed by an Ashikabi prior to reciting it. Sekirei that are under the same Ashikabi can also merge their techniques in order to create more powerful techniques. This puts most Ashikabi at a disadvantage, as only a few Ashikabi possess more than one Sekirei.