Answer:
Western Europe
Step-by-step explanation:
During the middle age eras, Societies in Western Europe and Japan operate their countries In a Feudal system.
In Feudal system, the lands in the country are owned by several different lords. These lords then give 'permission' to the people to take care of the land in their behalf. In return, these people will be given a small percentage from the result of their work,
The way they structure their military also similar. Rather than a centralized military, the Lords in each territories are the one that is responsible to manage the military. These lords could act independently. Meaning that if the King requested a military help from one of the lords, the lords could technically refuse that request. This would be impossible under a Monarchy.