Ustio, officially the Republic of Ustio, is a small landlocked nation located on the Osean continent. It is bordered by Belka to the north; Recta and Ratio to the east; Sapin to the south; and Osea to the west. Ustio's capital, Directus, is situated near the center of the nation.
Formerly Belkan territory, Ustio seceded from the Belkan Federation as a result of the Belkan economic crisis, declaring its independence on May 12, 1988. In 1995, Belka invaded Ustio as part of the Belkan War.