As servants of the daimyos, or great lords, the samurai backed up the authority of the shogun and gave him power over the mikado (emperor). The samurai would dominate Japanese government and society until the Meiji Restoration of 1868 led to the abolition of the feudal system.
I would try inequalities in the tax structure. The rich were paying less but getting more out the system. Poor could not even buy food. (Let them eat cake.)
