A medium size planet with a large temperate zone. Four major continents, the two largest sitting at roughly the same latitude (though the Eastern continent reaches further South). There is also a smaller Northern continent separated at one point from the Western continent by a few kilometers; and an archipelago referred to as the Southern Continent. Some islands there are somewhat large (but not continent-sized). Celesians refer to the area as a continent anyway.

For a millennia Celes has been ruled by the Houses, each Celesian born into one and usually related to everyone else in the same House by blood. The Houses are responsible for the education, protection, and discipline of their members. Most Celesians marry within their own House, occasionally marrying into another House for personal or political reasons. Celesians have three names: their given name, their bloodline, and their House name. The bloodline is traced through the mother, while House name is logically determined by what House the Celesian belongs to. Most Celesians are born into the House of their father, as the society is traditionally patriarchal.

Each House has a head, decided by both birth and vote. The list of candidates is made up of the offspring of current and recent rulers (first cousins often compete for the leadership, a statute-of-limitations exists on how far the eligibility extends beyond that relationship). If only one candidate exists, they win by default (however, this has been unnecessary as each leader always had sufficient heirs).

Since each House is consisted of people who are related to each other, the governmental style has a very close and intimate feel to it. Justice varies widely between Houses (as it does between normal families). In the smaller Houses it is not uncommon for the leader to know every member of their House.

As Celes became more advanced and Houses came into more contact with each other, it became necessary to establish a central government to coordinate relations between Houses and handle any planetary matters. This Council deals with issues of trade, inter-House disputes, the environment, and now education (as large differences between the educational systems of each House was becoming a hinderance to societal development). They also had a small planet-wide military. Each House has one representative on this Council, though others wield more power due to representing a larger House. The larger Houses are older and more established, and are sometimes referred to as the "Great Houses" even though this is discouraged in the name of unity. The larger Houses for the most part hail from the three continents, while most of the smaller Houses hail from the Southern archipelago or more rural areas on the major landmasses.

Roughly 15 years before the story started a civil war broke out on Celes. The leader of House Montegue led the "Lesser" Houses in a revolt against the Great Houses, leading to the murder of most of the leaders and their families. Some Houses were wiped out completely (like the Marcanas, the current Council leaders). This left a power void which the leader of House Montegue filled by forming a unified government with him in charge. The various militaries were merged into a powerful force capable of challenging other planetary governments.

The war left a large number of orphans who had no place to go, since their entire extended family had been wiped out, or whatever blood relatives they did have were unwilling to take them in for fear of reprisal. These children ended up in camps and orphanages, some formed gangs to replace the Houses they had lost, and many orphaned teenagers joined the Celesian military.