Back in the Samurai days of Japan, Samurai warriors were hired by lords to defend their lands and help expand their territories. They were expected to have full and complete dedication to their master and be willing to die for them at a moments notice. That is why samurai warriors always carried two swords, a large one for fighting and a smaller one for Seppuku (ritual suicide). After the samurai died off in the 19th century, a new national movement started (the Meiji period to the Shōwa era) to modernize the country and to build up the nations military. This changed the focus from serving one's lord to serving one's country. So much so, that there were great worries that at the end of World War II, there might be national suicide committed in the shame of losing the war. Oh course this thankfully never happened but the culture once again shifted. This time the dedication moved from loyalty to the nation to loyalty to one's company.
Akira Kurosawa made 30 films in his 55 year career. Although known for his samurai films, only 9 of those take place in samurai times. Most of Kurosawa films were contemporary films that dealt with the struggles of post-war Japan. The Bad Sleep Well was made in 1960 at the peak of his creative and commercial appeal but it is not as well known as his other masterpieces like Seven Samurai, The Hidden Fortress and Yojimbo.
Loosely based on Hamlet, it tells the story of Koichi Nishi (Toshirō Mifune) that is out to seek revenge of the death of his father. It is a scathing expose of the corruption of big business in Japanese companies. Western audiences in particular have never warmed up to this picture due to many cultural differences in the film. Many of characters of the story have an unwavering loyalty to their company and many of the employees in the film are willing to steal, cover-up and even kill themselves to protect the company and their employer. This can be a little jarring to understand why employees would be so loyal, when their bosses are so corrupt.
So to best understand it, is good to look at this film as modern samurai film. The President of the company is the feudal lord, the upper and middle management are the samurai and the workers are the farmers. In this context The Bad Sleep Well is a fantastic film that not only makes a commentary of modern Japan but also the social structure that has remained in place regardless of the changes in history.