Nuhi (slave) (奴婢)
Nuhi refers to one of the positions of Senmin (unfree people) against Ryomin (free people) under the ritsuryo system (the system of centralized government based on the ritsuryo code), and was equivalent to a servile class. Nu refers to a male slave. Hi refers to a female slave.
Nuhi generally received restrictions on freedoms to choose an occupation, to have a family and to choose where to live, and was sometimes emancipated at a certain age or under some conditions. However, Nuhi was basically treated in the same manner as livestock, and was traded at a market and so on.
Slavery system in China
The slavery system itself was officially incorporated in the national system under the ritsuryo system, but there had been a discrimination between Ryomin and Senmin before that time, and various kinds of limitations were put on Senmin. Senmin was largely divided into Nuhi and others, and Nuhi was divided into Kannuhi owned by the government and Shinuhi owned by individuals.
In the periods of Qin and former Han dynasty, Kannuhi whose core consisted of prisoners of war and clans committing a serious crime was mainly engaged in the work at a government-owned factory or in breeding horses, birds, dogs and so on at a stock farm. Meanwhile, Shinuhi mostly consisted of bankrupt peasants, and was often engaged in farming work or other routine tasks for local large landowners.
In the periods of Northern Wei, Sui and Tang, Shinuhi who was incorporated in the ritsuryo system and was put under the control of the master, received restrictions including being disallowed to sue the master.
In the periods of Ming and Qing, Nuhi still existed, but mainly consisted of Shinuhi basically, and disappeared gradually. However, in the 19th century, a coolie which could be a replacement appeared. These systems were officially abolished when the People's Republic of China was formed.
Slavery system in Japan
The slavery system in Japan was introduced upon amending the ritsuryo systems of Sui and Tang to a Japanese style when introducing them.
As shown by a description in Gishiwajinden (literally, an 'Account of the Wa' in "The History of Wei Dynasty") of Sangokushi (Three Kingdom Saga), that more than 100 Nuhi were buried together as martyr to duty when Himiko (first known ruler of Japan) died, and another description that slaves (or captives; there is another theory) called Seiko were brought to the Wei dynasty (Three States Period) as a tribute, Nuhi itself already existed at least in the period of Yamatai Koku (Yamatai Kingdom). It is considered that the slavery system in Japan was formed as a result of reordering such Nuhi who had existed since ancient times at the time of introducing the ritsuryo system.
Senmin under the ritsuryo system was called Goshiki no sen (the base people of five colors), and was divided into five ranks. Among them, Nuhi ranked as the lowest. Nuhi was largely divided into Kunuhi (government-owned slave) and Shinuhi. It is said that the Nuhi made up about 5% of the population under the ritsuryo system in Japan.
Kunuhi served the imperial court, and was engaged in routine tasks. Kunuhi seemed to be incorporated in Kanko (slaves to public ministries) once passing the age of 66, and to be emancipated as Ryomin at the age of 77.
Shinuhi refers to Nuhi owned by powerful local clans, and such clans could inherit Shinuhi from generations to generations. Shinuhi received one third of the total Ryomin as Kubunden (rice fields given to each farmer in the Ritsuryo system).
The slavery system in Japan disappeared along with the collapse of the ritsuryo system, and in the 900s, an edict to abolish the slavery system seemed to be already promulgated.
Senmin as a slave disappeared in an early period, but Senmin as a discriminated class (so-called "Eta" [one group comprising the lowest rank of Japan's Edo-period caste system, people whose work usually involved handling human bodies or animal carcasses] and "Hinin" [one group comprising the lowest rank of Japan's Edo-period caste system, often ex-convicts or vagrants]) started appearing obviously in the medieval period, survived throughout the early-modern times, and existed until Kaiho Rei (Emancipation Edict) was promulgated in 1871.
Slavery system in Korea
The slavery system also existed in Korean Peninsula, and in the Joseon Dynasty, Senmin was largely divided into Nobi (slave) and Baekjeong (inferior servants). Among them, Baekjeong was ranked as the lowest.
Nobi who was divided into Kannuhi and Shinuhi, received restrictions on freedoms to choose where to live, to marry and to choose an occupation, and was tradable at a market legally. However, Nobi was emancipated in some cases. Some of the Kannuhi were richer than local peasants because they collected taxes as a proxy. Furthermore, by reason that Nobi who caused a rebellion at the time of the Bunroku War put an administrative institution on fire, and burned the family register, and for the purpose of earning expenses of the war, Nubi who paid a certain amount of money was allowed to become Ryomin. This is why the class system fell into disorder, and Nobi decreased from 37% to 2% in one region, but such event caused a situation that Yangban (traditional ruling class or nobles of dynastic Korea during the Joseon Dynasty) who made up only 9% of the population increased to 70%.