Demographic history of Japan before the Meiji Restoration

Demographic features of the population of Japan before the Meiji Restoration include aspects of nationality, religion, and ethnicity.
Before the establishment of the religious and population investigation registers system by the Tokugawa shogunate, several less reliable sources existed upon which an estimate of the population was made. The first record of the population was the Chinese text "Records of Three Kingdoms" where the summated number of houses in eight countries of Wō is given as 159,000.
The household registration system (Hukou (simplified Chinese: 户口; traditional Chinese: 戶口; pinyin: hùkǒu) or Huji (simplified Chinese: 户籍; traditional Chinese: 戶籍; pinyin: hùjí)), which is called koseki (戸籍, family registries) in Japanese, was introduced from ancient China to Japan during the 7th century. According to "Nihon Shoki (日本書記)", the first koseki system, called Kōgo no Nen Jaku (庚午年籍) or Kōin no Nen Jaku (庚寅年籍), was established between 670 or 690, and was to be readministered every six years. However, most of the original koseki texts were lost because they were to be preserved only 30 years. The oldest koseki fragments - which were reused as reinforcement papers (Shihai Monjo (紙背文書, scroop document)) in Shōsōin (正倉院) - records names, ages and estates of people including slaves (e.g. 1,119 persons were recorded for the village named Hanyū (半布里) (present day Tomika-chō (富加町)) in 702)). A discarded lacquer-coated paper document (Urushigami Monjo (漆紙文書, lacquer paper document)) found in Kanoko C Ruins (鹿ノ子C遺跡), Ishioka, Ibaraki records the total population of families of taxpayers in Hitachi no kuni (常陸国) in 795 was 191,660 (excluding families of officers, families of workers for Shintō shrines and slaves); this is the only reliable remaining census recorded for a whole province before the Edo period. The ancient koseki system later collapsed during the early Heian period, when aristocrats achieved power as landowners of Shōen.
The following estimates by different scholars are based upon the number of houses, villages, kokudaka, areas of rice fields and soldiers which were recorded in "Wamyō Ruijushō (和名類聚抄)" (10th century), "Record of Song or History of Song (Chinese: 宋史; pinyin: Sòng Shǐ)", "Shūgaishō (拾芥抄)" (14th century), "Tenshōki (天正記)" (late 16th century), "Tōdaiki (当代記)" (early 17th century), or fragments of papers of the Shōsōin (8th century) and others, as well as remnants of specific periods.
Since Kyōto (or Heian-kyō) became the capital of Japan in 794, it has been one of the most important cities in Japan. Hiraizumi and Kamakura flourished under Northern Fujiwara clans (during 12th century) and Kamakura shogunate (1192 to 1333), respectively. The urban area of Kyōto suffered from the Ōnin War (1467 to 1477) and split into two districts, but coalesced into a great city of more than 400,000 inhabitants after the end of Sengoku period. The Christian missionaries led by Francis Xavier reported that the number of houses in Kyōto, Yamaguchi or Hakata was more than 90,000, more than 10,000 or 10,000, respectively, in the late 16th century according to History of Japan written by Luís Fróis. After the unification of Japan by Toyotomi Hideyoshi, Ōsaka grew into a populous city with tens of thousands of people. Several castle towns also began to grow, where samurai classes were settled.
After the Shimabara Rebellion, several daimyōs adopted certification systems where all the individuals were to be registered to temples and shrines to avoid Christianity. The Danka system (or terauke seido (寺請制度, temple-certification system)) was officially set by Tokugawa shogunate in 1664, and demographic data of individuals registered to temples and shrines (Shūmon Ninbetsu Aratame Chō) were recorded. After decades, Tokugawa Yoshimune decided to survey the total population of Japan and ordered to collect demographic data of all the domains (han (藩)) and shogunate territories (tenryō (天領)). The first census was surveyed every six years since 1721 and finished in 1846, because the confusion after the Perry Expedition and death of Tokugawa Ieyoshi in 1853 postponed the calculation process of the demographic data collected in 1852, according to Suijin Roku (吹塵録) edited by (Katsu Kaishū (勝海舟).
Some of population censuses during Edo era remain recorded in diaries or official texts as below. The population of samurai class and their servants as well as imperial families and noblemen was officially excluded from the census. In addition, the demographic data were summarized by individual domains according to their rules, where babies and children, Buddhist monks, nuns and Shintō priests, discriminated classes of eta and hinin were sometimes excluded from the total population. Unregistered people were also excluded.
In 1732, Tokugawa Yoshimune also ordered nine big Tozama daimyōs whose Domains were not changed since 1664 to report earlier population growths in their Domains. Here, population of Morioka Domain increased from 245,635 in 1669 to 322,109 in 1732; population of Tokushima Domain increased from 308,880 in 1665 to 470,512 in 1732; population of Tsu Domain increased from 252,061 in 1665 to 287,242 in 1732; population of Okayama Domain increased from 185,043 in 1686 to 396,469 in 1732; population of Kagoshima Domain increased from 260,961 in 1698 to 339,955 in 1732; population of Sendai Domain increased from 599,241 in 1690 to 647,427 in 1732; population of Tsuruoka Domain increased from 126,383 in 1694 to 131,164 in 1732; population of Kaga Domain increased from 551,754 in 1720 to 576,734 in 1732; while population of Nihonmatsu Domain only decreased from 73,351 in 1685 to 70,614 in 1732, according to the records written in "Chikkyō Yohitsu Besshū", which supports the rapid population growth in the early Edo era.
The total fertility rate is the number of children born per woman. It is based on approximated and fairly good data for the entire period. Sources: Our World In Data and Gapminder Foundation.
Some demographic data for former provinces or kuni (国) remain recorded. Similarly to the total population, recorded provincial population excludes ruling and exceptional classes, while that in 1873 (after Meiji Restoration) includes all the registered people.
After the beginning of the Tokugawa census, population growth fell almost to zero until the end of the Sakoku policy. On the other hand, regional demographic data suggest that population growth differed depending on area; the population of Tōhoku region (Mutsu and Dewa), especially in Mutsu decreased drastically, probably because of famines. The population of Kansai region (Kinai and its surrounding areas), which was the most densely populated and the most cultivated area of that time, as well as that of Kantō region, also slightly decreased, probably because the surplus population in the rural areas moved to the big cities such as Kyoto, Osaka, and Edo, where the life expectancy at birth were much lower than that in rural areas. On the other hand, populations in most of western Japan including Chūgoku region (San'indō and San'yodō), Shikoku (Nankaidō except for Kii) and Kyūshū (Saikaidō) steadily increased, where growth was sustained by the introduction of New World crops such as sweet potato, pumpkin, or corn.
The populations of Ryūkyū and Amami Islands were surveyed by the Satsuma Domain, which had formal possession of Satsuma, Ōsumi and part of Hyūga (Morokata-gun (諸県郡)) in southern Kyūshū, and recorded in Satsuma domestic texts, although they were not reported to the Tokugawa shogunate and were thus excluded from the total population of Japan. The populations of Ryūkyū and Amami Islands were included in the total populations of Japan after the Meiji Restoration.
The populations recorded in Satsuma domestic texts include all the classes, from several samurai classes to people who were discriminated against.
On the other hand, the populations of Ainu in eastern Ezo (including Chishima (Kuril Islands)) and western Ezo (including Karafuto (Sakhalin)) have been recorded since 1798 and 1810, respectively, and were thus included in the total population of Japan.
Meiji government tried to unify the registered system of Shūmon Ninbetsu Aratame Chō in consonant with that of each other among domains and prefectures into a single registered system of koseki. However population were still surveyed by domains until the Abolition of the han system in 1871. The total population of Japan on July 28, 1870 (32,773,698) was collected by different systems of domains, but included all the registered people of all classes.
The uniformed system of Jinshin koseki (壬申戸籍) was finally established in 1872, where the discriminated classes of eta and hinin were assimilated into the citizens class (heimin (平民, normal people)), though they kept unofficially called shin-heimin (新平民, new normal people)) and discriminated. The honseki population in 1872 (33,110,825) includes 29 imperial members (kōzoku (皇族, imperial family)), 2,666 noblemen (kazoku (華族, noble family)), 1,282,167 former samurai class members (shizoku (士族, samurai family)), 658,074 and 3,316 lower former samurai class members (sotsuzoku (卒族, soldier family) and chishi (地士, squire), respectively), 211,846 and 9,621 Buddhist monks and nuns (sōryo (僧侶, monk) and ama (尼, nun), respectively), 102,477 former Shintō priests (kyū-shinkan (旧神官, former Shintō priest)), 30,837,271 citizens (heimin, which includes ca. 550,000 shin-heimin and 2,358 unclassified people in Sakhalin.)
After the Battle of Sekigahara, Yamaguchi declined, while Edo (Tōkyō) and Sumpu (Shizuoka) became important under the Tokugawa shogunate. According to Rodrigo de Vivero y Velasco, the populations of Kyōto, Ōsaka, Edo, Sumpu and Sakai were 300,000–400,000 (or 800,000), 200,000, 150,000, 120,000 and 80,000, respectively, while the two towns between Sumpu and Kyōto had 30,000 and 40,000 inhabitants (probably Hamamatsu and Nagoya (or Kiyosu), respectively) in 1609. After the death of Tokugawa Ieyasu, Sumpu became less important, while Edo, Ōsaka and Kyōto became the three most important cities and were called the santo (三都, three capitals) with tens of thousands of inhabitants.
Below is a list of the estimated population of major Japanese urbans during Edo period. Although Hiroshima, Wakayama, Tokushima, Hagi, Takamatsu and Sumpu (Shizuoka) were important castle towns of major domains, estimated populations are not given because of the lack of sufficient demographic records. Population of Shuri, the capital of the Kingdom of Ryūkyū, is also not estimated, while Yokohama was only a small village of less than 100 houses until the opening of the port in 1859.
Estimated populations of castle towns contain considerable errors compared to those of the business towns (Ōsaka, Sakai, Hyōgo, Niigata, Nagasaki, Hakodate and Fushimi) with fewer samurai-class inhabitants, because demographics of samurai classes and their servants (or dwellers of samurai districts) were recorded separately or kept secret, which easily lead to the loss of original data after the abolition of the Han system. On the other hand, the demography of chōnin classes (civilian), or dwellers of chōnin districts plus chōnin classes who dwelt in temple/shrine districts (i.e. excluding demographics of Buddhist monks, nuns and Shintō priests which were usually summed separately), rather remain recorded for most of the cases.
Even the peak estimated population of Edo varies from 788,000 to 1,500,000. For example, Yoshida (1910) estimated the peak population of Edo (shortly before Perry's expeditions) at 1,400,000 based on the average amount of rice carried into Edo (1,400,000 koku per year). Chandler (1987) estimated the peak population of Edo at 788,000 by adding samurai population as 3/8 of the recorded chōnin population. Sekiyama (1958) estimated the peak population of Edo at 1,100,000 by adding samurai and servants population as 500,000 (215,000 Hatamoto, Gokenin, their servants and families, 100,000 shōgun's Ashigaru, other lower servants and their families, 180,000 Daimyo, their servants and their families). Diaries recorded that the population of Edo was 1,287,800 in 1837, the population of monks and priests was ca. 40,000 or the samurai population of Edo was 700,973. According to the map of Edo illustrated in 1725, area for samurai occupied 66.4% of the total area of Edo (estimated population density: 13,988 /km for 650,000 individuals), while areas for chōnin and temples-shrines occupied 12.5% (estimated chōnin population density: 68,807 /km for 600,000 individuals) and 15.4% (estimated population density: 4,655 /km for 50,000 individuals), respectively.
Selected recorded populations of urbans listed above are as follows. Sources for koseki censuses are given in Japanese Wikipedia page.