Shunjū Country

The Shunjū Country (春秋の国 Shunjū no Kuni), more formally the Shunjū Allied Nations (春秋連盟国 Shunjū Renmei Koku), is an alliance of five powerful nations.

It is one of the few countries legally independent of the World Empire, and is located on an isolated continent.

Member Nations
The Member Nations (会員国 Kaiin-goku) are the five affiliate states of the Shunjū Country. They serve as the country's official military force, and train samurai in case of war—usually against foreign nations, but occasionally against unofficial states as well.

Warring States
The Warring States (戦国 Sengoku) are the unofficial states—not members of, but simply within territory—of the Shunjū Country. They often wage war to show off their military strength and become acknowledged (i.e. becoming a member nation). They train samurai as well, but may hire ninjas from hidden villages to aid them.

Hidden Villages
The Hidden Villages (隠れ里 Kakure-sato) are neutral villages that, instead of raising samurai, train ninja to become mercenaries. They may aid any country at times of war.

Trivia

 * The term Shunjū Sengoku (春秋戦国), literally meaning "Spring and Autumn Warring States," refers to late Zhou Dynasty. It's actually a compound term used in north-east Asia, referring to both the Spring and Autumn Period and Warring States Period as a whole.
 * The idea of hiring ninjas from villages was inspired by Naruto, though the concept was reversed—ninja are more neutral as opposed to the warring samurai.