Some things in the game have a direct connection to a country in the real world. For example, the Lionheart Honor Blade is connected to Great Britain's King Richard. Gunslinger gear references the USA’s cowboy culture of the 19th century, as does the Argent Peacemaker gun owned by Wild Bill Hickok.
There are also two items (well, more really since one of them has different versions) that have a direct connection to Japan.
The first is the maedate accessory .
The various maedate became a standard feature on the samurai kabuto war helmets.
It was the samurai who created the guiding principles of honor, duty to one's master, and loyalty unto death that came to be known as bushidō. The samurai were the ruling class and, therefore, were less than 10% of Japan's population.
However, bushido continues to be part of modern Japanese life in both the corporate world and martial arts such as judo, kendo, and karate. The samurai were also well-educated, so after the samurai period ended in the mid 1800’s, some became the literary force in Japan and naturals for government office.
The militarized era of the samurai is full of heroism and tragedy and a favorite movie genre, but I personally view it as rather a dark time in the history of these islands.
The second connection is, of course, the Costume shogun helmets found in the original heavy reddish, as well as the new bright red raging version and shiny golden storm versions.
All three are equipped with the requisite maedate.
A shogun was like a local king. They were really generals who had to answer to the Imperial court, but the court’s power was mainly symbolic rather than military. Therefore, the shogun were the de facto rulers in Japan.
What other things in the game are connected to a real country?
P.S. If you’d like to read more about Japan, you can check out my Life in Japan thread in Gremlin Chatter.
This question comes up all the time, in various forms. Check out the wiki article "List of References", and search Google for something like "references site:forums.spiralknights.com". You will find many threads to satisfy your curiosity.