There is a thesis that one of the main reason Hideyoshi ordered invasion of Korea was to actually get rid of the dregs of Sengoku period, if they succeeded it would be a bonus But they failed on both fronts what ensued was three biggest and bloodiest civil wars campaigns in feudal Japan history, only then they settled up and became one of the most useless parasitic classes in history of mankind. And eventually they got outparasited by usurers and become prime source of imperialist lackeys.

There's fun (and actually non bloody or horrible for once) example of the real Samurai ethos i read in book. I think it was in XVIII century, when a small and pretty isolated garrison of 200 men in mountains of central Japan got denounced to bakufu, and inspection turned out that basically nobody there was doing any samurai things, most of them even sold their swords and entire garrison just said "fuck this" and they were working in nearby pottery. Normally this would be horrible scandal ending up in the mass suicide order (bakufu did such things), but this particular pottery was famous for producing very high quality tea sets for arsitocrats so entire case was hushed.