In ancient Japan, samurai were a special social class. They were allowed to wear two knives and had the power to kill civilians. From the 10th century to the 19th century, it has a history of hundreds of years. Samurai have their own loyal Lord. When Samurai loses his Lord, he will become a ronin.
In Japanese culture, Bushido has many positive norms, such as loyalty, courage, faith, benevolence, righteousness and so on. But in reality, many Samurai have shown their ignorance, madness and ferocity. So some people say that those positive norms are just superficial phenomena.