Reference · Updated October 2026

Glossary of Japanese family-history terms

The words you will meet in koseki, village histories and our reports, explained in a line or two. Kanji are given once so you can recognize them on documents.

People and generations

Issei / Nisei / Sansei / Yonsei / Gosei

First, second, third, fourth and fifth generation counted from the immigrant. The Issei were the ones who left Japan.

Nikkei

People of Japanese descent living outside Japan, of any generation.

Kenjinkai 県人会

An association of emigrants from the same prefecture, found in Honolulu, Los Angeles, Vancouver, São Paulo and elsewhere. See our kenjinkai guide.

The family register

Koseki 戸籍

Japan's family register. One record per household, listing births, marriages, adoptions, deaths and moves. Kept since 1872; copies are available back to the 1886 format.

Honseki 本籍

The "registered domicile": the address under which a family's koseki is filed. Often the ancestral village, even for people who lived elsewhere for decades. See how to find your honseki.

Index person 筆頭者 (hittōsha)

The person whose name indexes a modern register (from 1948), listed first; the name stays even after that person dies. Not the same as the pre-1948 head of household (koshu; see "House and headship").

Register

On our price list, one certified document from the city office (one closed register or one pre-reformat register), however many pages it has.

Closed register 除籍 (joseki)

A register everyone has left through death, marriage or moving away. Most emigrant-era registers are closed registers.

Pre-reformat register 改製原戸籍 (kaisei-genkoseki)

The older version of a register, kept when the legal format changed (1886, 1898, 1915, 1948, 1994). Each format change left a copy you can still request.

House and headship 家・家督相続 (ie, katoku sōzoku)

Until the postwar reforms of 1947–48, Japanese law organized families into "houses." The head of household (koshu, 戸主; before 1948) held the house and passed the headship on (katoku sōzoku), usually to the eldest son. A new head opened a new register, and the old one was closed.

Branch household 分家 (bunke)

A new house set up by a younger son or another member of an existing house, with its own register. The original house is called the main house (honke, 本家).

Gyōseishoshi 行政書士

A licensed Japanese administrative scrivener. By law, only licensed professionals may prepare and file official requests for others for a fee.

Banchi 番地

The lot number in a Japanese address.

Aza 字

A hamlet or named section within a village; often the address level of the honseki.

Places and administration

Prefecture 県 (ken)

Japan's 47 regional units, created in 1871 (roughly a US state or Canadian province).

District 郡 (gun)

A rural county within a prefecture, still used in some rural addresses today; "Aki District, Hiroshima" is such a district.

Village / town / city 村・町・市

Municipalities. Most villages of 1889 have since merged into towns and cities, so an old village name usually points to a modern city office.

Province 国 (kuni)

The pre-1871 regional units (for example Bungo, most of today's Oita Prefecture). Used in historical records.

Domain 藩 (han)

One of about 260 fiefs ruled by hereditary lords under the shogun (Japan's military ruler) in the Edo period (1603–1868). A village "belonged" to a domain, which taxed it. Domains sometimes had detached holdings far from their castle.

Daimyo 大名

The lord of a domain.

Estate 荘園 (shōen)

A medieval landholding owned by a temple, shrine or noble family and worked by local households.

Land steward 地頭 (jitō)

The warrior appointed in the medieval period to police and collect taxes on an estate.

Myō 名

A medieval unit of taxable fields, often carrying a family's name; the origin of many place names and surnames.

Gazetteer 郡誌・県史

A local encyclopedia of a district or prefecture compiled, usually in the 1910s–1930s, from older documents and local tradition. Reliable for the outline, weaker for detail.

Society and status

Village headman 庄屋・名主 (shōya / nanushi)

The hereditary local official who ran a village for the domain: taxes, disputes, records. Typically, the wealthiest farming family, literate and often related to local warriors.

Commoner 平民 (heimin)

The legal status entered in koseki from 1872 for farming, merchant and artisan families, as distinct from the samurai class. Like shizoku (see below), it was dropped from registers when the Family Register Act took effect in 1948.

Samurai / shizoku 士族

The hereditary warrior-administrator class of the Edo period (1603–1868); recorded as "shizoku" in koseki until the postwar Family Register Act took effect in 1948.

Local warrior 国衆・地侍 (kunishū / jizamurai)

A land-holding family that fought for a regional lord while farming its own land. Many Edo-period headmen descended from them.

Retainer 家臣 (kashin)

A warrior in the service of a lord.

Court-style title 官途名 (kanto-mei)

An honorary name modeled on an ancient court office, granted by a lord to a retainer (for example Kunai-no-jō, Izumi-no-kami). Not a real office; treat it as part of the name.

Nyūdō 入道

"Entered the Way": a warrior who had taken Buddhist vows but stayed active in worldly affairs.

Everyday name / formal name / courtesy name / pen name

Men of standing used several names at once; the everyday name (for example Teigorō) was often handed down from father to son.

Family crest 家紋 (kamon)

A hereditary emblem used on kimono, gravestones and shop signs. Used by commoners as well as samurai.

Family temple 菩提寺 (bodaiji)

The Buddhist temple that holds a family's graves and memorial records. Under the Edo-period parish system every household had to register with one.

Death register 過去帳 (kakochō)

A temple's book of posthumous names and death dates; the main source for the generations before 1886, where it survives and the temple allows access.

Religious census register 宗門改帳 (shūmon aratame-chō)

The Edo-period household census taken through temples; an ancestor of the koseki.

Memorial tablet 位牌 (ihai)

A lacquered tablet in the family altar bearing a deceased person's posthumous name and death date.

Butsudan 仏壇

The Buddhist family altar in a home.

Time and measures

Era name 年号 (nengō)

Japan counts years by imperial era: Meiji (1868–1912), Taishō (1912–26), Shōwa (1926–89), Heisei (1989–2019), Reiwa (2019–). "Meiji 15" = 1882; Meiji 1 = 1868, Taishō 1 = 1912, Shōwa 1 = 1926.

Lunar calendar

Used until 1872. Months ran 3–7 weeks behind Western months; a leap ("intercalary") month was added about every three years. An "intercalary 3rd month" is a second 3rd month that followed the ordinary one.

Counted years 数え年 (kazoedoshi)

The traditional way of stating age: one at birth, plus one every New Year. Usually one or two years higher than Western age.

Historical periods and events

Kamakura (1185–1333), Muromachi (1336–1573), Warring States period, Sengoku (c. 1467–1600), Edo (1603–1868), Meiji (1868–1912)

The periods you will meet most often. See the two-minute guide to Japanese history in our sample Roots Report.

Meiji Restoration (1868)

The fall of the shogun and the start of the modern state, which brought surnames for all, the koseki, conscription, schools and emigration.

Imperial Diet

Japan's first national parliament, opened in 1890.

Ōtomo clan

The warlords who ruled Bungo (Oita) and much of northern Kyushu for 400 years until 1593; their retainers appear throughout the records of the Kunisaki Peninsula (Oita), where our sample family lives.

Rokugō Manzan

The network of Tendai Buddhist mountain temples unique to the Kunisaki Peninsula, recorded since the 8th century. Tendai is one of Japan's major Buddhist schools.