"How Far Back Can My Family Tree Go?"
This is a question that everyone asks when they start building a family tree.
The short answer: using koseki (family registers) alone, you can reliably trace back to roughly the late Edo period to early Meiji era (the late 1800s). However, by combining koseki with other research methods, it's possible to reach back into the Edo period — and sometimes even further.
This article explains the limits of koseki records and introduces practical methods for finding ancestors beyond those limits.
The Limits of Koseki Records
The Beginning of Japan's Koseki System
Japan's modern family register system began with the Jinshin Koseki of 1872 (Meiji 5) — the country's first nationwide census-like registration system, recording every citizen.
However, the Jinshin Koseki contains discriminatory notations and is currently sealed from public access. The oldest registers we can actually obtain are the Meiji 19 format registers (from 1886 onward).
Retention Period for Koseki Records
The retention period for removed registers was originally 80 years, but a 2010 legal revision extended it to 150 years. This means Meiji 19 format registers are likely still preserved in many municipalities.
That said, some records were lost to war damage or natural disasters, so not all registers survive.
How Many Generations Can Koseki Trace?
By tracing all available koseki records, most people can identify ancestors 5 to 7 generations back — those born in the late Edo to early Meiji period. This is possible because older registers sometimes include information about the household head's grandparents or previous household heads.
In practice, the earliest ancestors identifiable through koseki were typically born in the first half of the 1800s.
Beyond Koseki — Methods for Finding Pre-Edo Ancestors
So how do you go beyond the limits of koseki to find even older ancestors? Here are several research methods that can extend your family tree further back in time.
1. Investigate Temple Death Registers (Kakocho)
A kakocho is a death register maintained by Buddhist temples. During the Edo period, the "temple certification system" (terauke seido) required every person to be affiliated with a temple. As a result, temples may hold records dating back centuries.
- How to investigate: Contact the temple where your ancestors' graves are located (bodaiji) and politely request to view their kakocho
- Important note: Kakocho contain personal information, so temples may decline your request. A respectful approach is essential
- Information available: Buddhist posthumous names, secular names, dates of death, age at death
With luck, you may be able to trace records back to the early Edo period (1600s).
2. Read Gravestone Inscriptions
Old gravestones often bear ancestors' names and dates of death. Edo-period gravestones sometimes include not only Buddhist names but also secular names (names used in life), making them valuable information sources.
- Tip: Check the sides and back of the gravestone as well. The name of the person who erected the stone can reveal previously unknown relatives
- Note: If inscriptions are weathered, techniques like wetting the stone or making rubbings can help
3. Research Local Historical Archives
Regional libraries and local history museums may hold documents from the Edo period:
- Shumon Ninbetsu Aratamecho: The Edo-period equivalent of a census, recording religious affiliation and family composition
- Kenchicho: Land survey records listing landowners — useful for tracing farming ancestors
- Domain records: For samurai families, domain personnel registers (bungen-cho) may list your ancestors
4. Research Your Surname and Family Crest
Investigating the origins of your family name can reveal clues about your clan's roots:
- If your surname derives from a place name, that location may be your family's ancestral homeland
- Family crests (kamon) are clan symbols — researching clans with the same crest can uncover historical connections
5. Use DNA Testing
Modern genetic testing services allow you to scientifically explore your ancestral origins:
- Trace maternal lineage (mitochondrial DNA) or paternal lineage (Y-chromosome)
- Discover ethnic roots spanning tens of thousands of years
- Note: DNA testing cannot identify specific individuals or family lines
Combining DNA results with documentary research provides a more comprehensive understanding of your ancestral roots.
Organize Your Findings into a Family Tree
Information gathered through these various methods only becomes meaningful when brought together in a single family tree.
Koseki data, temple records, gravestone inscriptions — connecting these scattered pieces into one coherent "family story" is like solving a puzzle, and it's an incredibly exciting experience.
The "Anotoki Kakeizu" app makes it easy to compile all this information. Record names, birthdates, and dates of death, and use the memo field to note temple information and Buddhist posthumous names. You can also set family crests, ensuring your clan's complete history is preserved.
Experience History with the Time Machine
The Time Machine function in "Anotoki Kakeizu" lets you animate your family history from 1600 to the present day.
How did your ancestors living in the Edo period experience the turbulent final years of the shogunate? How old were they during the Meiji Restoration? When you spot your own ancestors within the great sweep of history, you'll feel a chill of excitement run through you.
Export and Share in Multiple Formats
Export your family tree in PNG, PDF (A4/A3/Letter), CSV, GEDCOM, JSON and more:
- Print a high-quality PDF to present at family gatherings
- Export as GEDCOM for compatibility with other genealogy software
- Share a PNG image to enjoy your family history with distant relatives online
Start Building Your Family Tree Today
Family tree research begins with koseki and expands outward to temples, gravestones, and local archives. Each step is a journey of weaving your own unique "family story."
"Anotoki Kakeizu" is free to download. Available for iPhone, iPad, and Mac, you can start building your family tree today.
Begin by entering the information from your koseki records to create the "trunk" of your family tree. As you add branches and leaves, you're sure to discover a family history deeper and richer than you ever imagined.