Jiyuuian is a cultural term that was invented by the citizens of the United Outer Colonies to differentiate themselves from the citizens of the Yamatai Star Empire. It is not an actual species.

Jiyuuians typically are:

1. People who were part of the UOC in YE 30 when it broke off from the YSE
2. born in the UOC during its brief existence
3. born to parents who consider themselves Jiyuuian

After the secession of the United Outer Colonies in YE 30, there was a question of what term to use to identify the species that made up most of the UOC. Most UOC citizens were culturally Yamataian and biologically Yamataian (NH-22C), although some transferred into UMC's Synthetic NI-ARIA bodies. There are also a handful of Nekovalkyrja that identify as Jiyuuians althoguh this is very rare, as Nekovalkyrja bodies were returned to Yamatai as Star Army of Yamatai equipment in the early days of the UOC.

A rebranding was needed. The term “Jiyuu” is Yamataigo (邪馬台語) for “Freedom” and the Jiyuu star system was the capital system of the newly-formed UOC.

Although the UOC failed and was dissolved in YE 33, the term stayed in use in some regions.

Most Jiyuuians that didn't die to the NMX in the Second Mishhuvurthyar War were evacuated to the Yamatai Star Empire and lived in Refugee Camps for a while. In YE 36, Yamatai began offering them return trips back home and the remaining camps closed as they emptied. By YE 38 the refugee camps were no longer necessary.

Others Jiyuuians were evacuated to the Democratic Imperium of Nepleslia. See Evacuation of the Tange System.

There are also some Jiyuuians who became part of the Lorath Matriarchy.

Since YE 42, the cultural concept of the Jiyuuian has faded in the Motoyoshi Colonial Sector as the Motoyoshi Clan pushed their campaigns and agendas through platforms like the Yugumo Workers Federation which exposed the criminal activities of the Tange Clan and the former United Outer Colonies. After the Attempted Terrorist Attack at YE 42 Lantern Festival, hold out citizens in UMC Synthetic Bodies rushed to transfer to Minkan bodies to show respect to the restored ruling clan and reject the agenda of the terrorists.

According to the United Outer Colonies, the Jiyuuians:

• speak Yamataigo (邪馬台語)
• tend to be very social, even if they do not know the others they are interacting with.
• avoid violence, only resorting to it in situations of dire circumstances.
• believe in social mobility, are against Slavery, and ownership of individuals.
• are deeply devoted to their families and friends.
• tend to be very proactive in promoting themselves, stemming from a lengthy history of being on the fringes of society when they were part of the Yamatai Star Empire.
• very accepting of other species; are interested in learning about new cultures.
• devoted to the foundations of peacekeeping and diplomacy.