Shi-no-ko-sho (hereditary four-status order consisting of warrior-rulers, peasants, artisans, and me (士農工商)

Shi-no-ko-sho was a Confucian concept of societal ranking (government official, farmers, artisans, merchants) that accounted for the main part of the society. It was also called 'Shimin' (the four social classes).
In Japan, shi '士' (government official) was replaced with '侍' (samurai or warriors), ko (artisans) and sho (merchants) were collectively recognized as townsman without being differentiated, and no order existed between peasants (no) and the 'townsmen.'

Summary
History
Originally, shi-no-ko-sho was a categorization of citizenry in the Spring and Autumn and Warring States periods in China (Shoshi hyakka (The Various Masters of the 100 Schools: Thinkers of Ancient China)), as described in "Kuan Tzu," 'the four social classes of government official, farmers, artisans, and merchants form the foundation of a country.'
Shi is the ruling class under which the other three classes lie. "Xun Zi" (or Hsun Tzu) and "Shunju Kokuryo-den" (Annotation of Guliang on Spring and Autumn Annals) described 'shi-sho-ko-no'; though in China, much more importance has traditionally been attached to "no" who settled in the land and produced crops, as opposed to the "sho" and "ko" who did not till the land and aimed at reaping profits. The thought was that if merchants and artisans were allowed to freely pursuit profits, their wealth would threaten the ruling class and farmers would give up the hard labor of agriculture start new careers as sho or ko, decreasing agricultural output, leading to famine, and resulting in the collapse of the social order. This theory was known as Confucianism; the teachings of Confucius. In Japan, however, the aspect of reisetsu (propriety) was received more favorably than Confucianism; thus, the Edo bakufu (Japanese feudal government headed by a shogun) designated the Shushigaku (Neo-Confucianism) which had always insisted on the importance of moral practice as 'kangaku' (a school of learning advocated by the Tokugawa shogunate).
"Nippo jisho" (Japanese-Portuguese dictionary) published by a missionary of the Society of Jesus in 1603 contained an entry on 'shi-no-ko-sho.'
This entry proved 'shi' already stood for samurai in these times.

Shi-no-ko-sho in the Early Modern Japan
Separation of warriors and peasants
The classes of samurai and peasants which had social mobility to some extent in the Warring States period (Japan) were fixed by taiko kenchi (the cadastral surveys conducted by Hideyoshi) which started around 1582 and katanagari (sword hunt) which was carried out in 1588. These policies which separated warriors and peasants were further enforced in the Edo period, and social mobility was reduced as a result. In Confucianism, it was thought that profit pursuing would lead to desires that would ultimately cause a human being to deteriorate and that activities of involved in commerce and industry themselves would be contrary to what a human being should be; nevertheless, under the above-mentioned circumstances, merchants took the initiative in an economy based on the development of a monetary economy and industry. As a result, in reality samurai became dependent on the merchants.

Actual class system
As described above, the theory of shi-no-ko-sho differed significantly from the actual class system. As the classes that were actually involved in systems in the Edo period, samurai were ranked at the top with 'peasants' and 'townsmen' just below. According to this system, peasants were grouped by village, townsmen by town, with no difference between their ranks. Townsmen were not distinguished systematically by their occupation whether they were 'ko' or 'sho,' and there was no system of discriminating merchants against artisans. Besides, peasants were not limited to living on farming and many of them actually built a fortune through marine transportation or handicrafts, which should have belonged to trades of 'sho' or 'ko'. An official announcement issued in October and November 1842 in the midst of the Tempo Reforms contained the following sentence: 'peasants must not start business of the townsman as a sideline' and set a ceiling on wages paid for employees who came from farming villages, all of which must have been countermeasures taken by the bakufu for fear that such tendencies would lead to a decline in agriculture. That is to say, hyakusho (peasant) in the current sense is a full-time farmer and categorized as 'nonin' (person engaged in agriculture); but in the Edo period, haykusho held a different meaning. Besides, only the head of the family was categorized under the peasant or the townsmen class in a strict sense, with subdivided classes in villages and towns. As shown in an empirical study which inferred that 'townsmen' and 'merchants' were categorized into different classes, the actual class system in the Edo period was quite a complex and complicated structure. A considerable portion of the population was excluded from the shi-no-ko-sho (such as court nobles, Buddhist monks, Shinto priests, kengyo (the highest title of official ranks within the Todo-za, the guild for the blind)), and these people also had respective official ranks. The actual class system of the Edo period remains unclear in many respects and has yet to be studied more closely based on empirical data.

Status mobility
Status was relatively flexible between peasants and townsmen, with status mobility also existing between those classes and low-ranking samurai (ashigaru (foot soldier)). On the other hand, little status mobility existed in middle and high ranking samurai. In order to move into another social class, the following measures were taken.

Adoption or marrying into a family.

Purchase of Gokenin-kabu (status of a low-level vassal of the Tokugawa shogun).

Promotion of a servant of a samurai family.

Employment as a steward. Becoming a wandering steward.

Going back to the land.

Focusing on the mobility to some extent between low-ranking samurai and high-ranking peasants, such classes may be called 'middle-ranking class.'
In addition, the peasants could be granted the privileges of having a family name, wearing swords, and taking lives of people with impunity, or status as a samurai. Still, these privileges and rank did not mean that the peasants became samurai.

Some people seem to think that there was a kind of 'freedom' in the Edo period based on this class mobility, however, the class system was a rigid framework that was also a highly flexible system which allowed for mobility. Therefore, the existence of class mobility did not mean that the class system was relaxed or dead in form.

Modern class system
In the Meiji period, it was considered that Japan would not be able to develop into a modern nation unless it broke away from its class system based in the medieval feudal society: therefore the government abolished the class system from the Edo period and enacted the policy of shimin byodo (the equality of four classes). Exceptionally, the ruling classes were granted titles of kozoku (the Imperial Family), kazoku (the peerage), and shizoku (samurai family) which they put on their family register. Kozoku, which still appeared in the systems after the war, indicates the Emperor and his relatives.

The title of kazoku was granted to the court nobles and the highest ranking samurai such as daimyo (feudal lord).

The title of shizoku was granted to the high ranking samurai.

The low ranking samurai, the peasants, the artisans, and the merchants were collectively categorized as 'Heimin' (commoner).

Here, it should be noted the treatment of senmin (humble people). As senmin were incorporated into heimin, some inherent heimin opposed this act, resulting in an ikki uprising in Okayama Prefecture to protest the treatment of the former senmin as heimin. For that reason, the term shinheimin (new commoners) was coined.

Interpretation by posterity
Historians after the Meiji period started to take the term shi-no-ko-sho as the real class system in the Edo period. Then, shi-no-ko-sho became an important concept in history, which created the common idea that there had been the order 'shi-no-ko-sho-eta-hinin (non-people)' by adding eta and hinin to shi-no-ko-sho. This kind of historical view after the Meiji period may have reflected the opinion of samurai who were based on Confucianism. After World War II, Marxian history began to define samurai as the ruling class and the peasants as the ruled class, emphasizing the misery of the peasants' life and the existence of a class struggle derived from this misery, with merchants as the bourgeoisies who accumulated property (capital) which ushered in the modern age. Around 1990s, an empirical study, which critically verified the above-mentioned concept of shi-no-ko-sho and used the primary sources of the same period as a basis, started to present a new concept of the class system in the Edo period. The term shi-no-ko-sho is currently a word which is prohibited on radio and television because the term has been associated with buraku-sabetsu (contemporary discrimination against burakumin (people who come from or live in special hamlets)).

Works featuring Shi-No-Ko-Sho
Music
Yotsu no Tami
This is a Jiuta piece in the Tegotomono style, composed for koto by a blind musician Matsuua Kengyo around the Bunka-Bunsei eras. Its poem likens shi-no-ko-sho to spring, summer, autumn, and winter, successively celebrating their positive points. This piece is considered a difficult piece of music with its complicated modulations, due to the shamisen's sophisticated technique for the long movement in the middle. This is considered as one of 'Yotsumono' (four famous pieces) of Matsuura. This piece was composed for koto by Kengyo YAEZAKI.

The comparison of shi-no-ko-sho to spring, summer, autumn, and winter may be associated with the concept of Wuxing (The Five Practices), and it is quite interesting that shi-no-ko-sho are compared to a cycle of four seasons so as to arrange the social statuses in a row instead of putting them in a hierarchical order.