The Japanese feudal system is one custom they had that kept society together, People Relied on others so much that they all respected each other greatly, and this made it fair and more likely to succeed. This custom helped the Japanese because the Shoguns, Daimyos, Samurais, and farmers helped each other. They all provided each other with the needs that help them survive. Without one class, They will not have what they need to live. Without feudalism, there would most likely be social ranking, where it would be unfair and less likely to succeed.
Amida and Zen Buddhism were two different types of Buddhism the Japanese practiced. Samurais were most interested in Zen because of its teachings in effort and discipline. Zen Buddhism helped structure society because it helped teach samurais to focus their minds and to overcome the fear of death. Without it, samurais would be concentrated on death, and not thinking about winning fights.
Bushido - The Samurais Code
Bushido is a code that means that a samurai should be honest fair, and fearless. Samurais also had to treasure loyalty and honor even more than their lives. Bushido played a great role in society because it helped Samurais to be loyal and respect everyone higher, or lower than them. It helps other classes trust them to be helpful and loyal during times of war and fighting. Without it, samurais could sabotage their lords, creating a time of disbelief, no loyalty, and could change the structure of Japanese society. This causes to have an error in the feudal system, and having a class not participate giving people protection when needed.