Tranquil Moon is an enlightened nation, it has a vast number of scholars and alchemists. It's people shun anything to do with the military so martial arts are rarely practised. The nation on a whole is also not spiritual. The people have a much more lenient sense of honour in Tranquil Moon. They are known for being calm and collected and very often passive to the point of inaction.
Brilliant Star is an empire where honour comes first. The governed by Shoguns who report to the emperor himself. It has many schools of sword ship where the nobles train but also there are reports of underground schools teaching weapons to peasants. The people of Brilliant Star are aspiring for greatness in service of the emperor. They are warm hearted but should not be insulted for fear of offending their honour.
Unyielding Earth is a large collection of nomadic clans. Normally a peaceful people there are times when a ruler has united the clans as a warrior nation. Their mounted archers are the best and most numerous in the land. The people have no sense of honour but should not be trifled with. They are stubborn and like an angry Taruos once they get going they cannot be stopped. This goes for individually as well as for the empire.
Refined Heaven is a deeply spiritual nation, it is also very enlightened. Monks and scholars learn there where often martial arts are taught alongside meditation or calligraphy. They keep largely to themselves rarely straying from their monasteries and cities. They are honourable but prefer not to hurt people so are less volatile that the people of Blazing Sun and Brilliant Star. Other than that not much is know about them as they are so rarely seen throughout the lands.