Welcome to the Genealogical Science Portal
This portal provides comprehensive information on institutions, services, and systems useful for researching Japanese ancestors and genealogy. Resources covering family registers (koseki), legal affairs bureaus, libraries, archives, temples, shrines, and online databases are organized by category.
Whether you are an overseas Japanese descendant or someone in Japan beginning ancestor research, find the resources you need here.
Browse by Category
📋 Family Register & Resident Records
How to obtain koseki tōhon, jokoseki tōhon, and kaiseigenkoseki—the foundation of Japanese genealogy research. Covers Ministry of Justice, MynaPortal, municipal offices, and overseas missions.
🏛️ Legal Affairs Bureau
Directory of all 50 Legal Affairs Bureaus in Japan. How to research real estate registration records to trace ancestral land ownership.
📚 Libraries & Archives
National Diet Library, National Archives, Historiographical Institute, all 47 prefectural libraries, and prefectural archives listed with addresses and links.
🎖️ Military Records & Pension
How to obtain military service certificates (gunreki shōmeisho) from the Ministry of Health and pension records (onkyū) from the Ministry of Internal Affairs.
💻 Online Databases
NDL Digital Collections, Japan Search, JAIRO, National Archives Digital Archive, Unified Koseki Character Information, Historical Administrative Area Dataset, and more.
🏯 Temples & Buddhist Denominations
All major Buddhist sects holding kakochō (death registers), with head temple locations and characteristics of posthumous Buddhist names (kaimyō) by sect.
⛩️ Shrines & Shinto
How to use Shinto shrine records (ujiko registers, donation records) for ancestor research. Overview of the Jinja Honchō and the ujiko parishioner system.
🔍 Kanji & Character Research
Tools for identifying archaic and variant kanji (itaiji) in historical koseki. Covers the MOJ Character Information Database, IVS standards, and the IPAmj font.
🏢 Private Services
How to access Zenrin residential maps via public libraries and other private services useful for Japanese genealogy research.
How to Start Japanese Genealogy Research
- Begin with koseki: Obtain your own koseki tōhon and trace backward through previous registers using the “jūzen koseki” (prior register) information.
- Identify the family Buddhist temple’s sect: Determine the sect from the ancestor’s posthumous name (kaimyō) and use the kakochō (death register) for pre-koseki records.
- Verify old place names: Abolished municipal names in historical koseki can be matched to current municipalities using the Historical Administrative Area Dataset.
- Supplement with libraries and archives: If koseki records were destroyed or are unavailable, supplement with village maps and religious population surveys (shūmon ninbetsu aratamechō) held in regional libraries and archives.