The Kazoku was the hereditary peerage of the Empire of Japan, which existed between 1869 and 1947. It was formed by merging the feudal lords (daimyō) and court nobles (kuge) into one system modelled after the British peerage. Distinguished military officers, politicians, and scholars were occasionally ennobled until the country's defeat in the Second World War in 1945. The system was abolished with the 1947 constitution, which prohibited any form of aristocracy under it, but kazoku descendants still form the core of the traditional upper class in the country's society, distinct from the nouveau riche.

Daimyo were powerful Japanese magnates, feudal lords who, from the 10th century to the early Meiji period in the middle 19th century, ruled most of Japan from their vast hereditary land holdings. They were subordinate to the shogun and nominally to the emperor and the kuge. In the term, dai (大) means 'large', and myō stands for myōden (名田), meaning 'private land'.