Methodology
Sources and Methodology
Calendar facts, historical interpretation, card-game rules, and product status need different sources.
Source Hierarchy
We prefer official Japanese government and cultural institutions, Japanese national or regional museums, Nintendo Museum for Nintendo/Hanafuda material, Japan National Tourism Organization for cultural and seasonal material, and academic or museum sources when primary material is not readily available.
Canonical Page Readiness
JapanAlmanac does not publish every possible event, prefecture, season, month, or date-window URL. A generated page needs enough structured facts, primary-source context, visible date confidence, verification information, planning value, and related Almanac material before it is indexable. Pages that cannot meet that threshold remain unpublished or noindex until the record improves.
Launch Source Register
| ID | Source | Use |
|---|---|---|
| nintendo-hanafuda | Try Playing Hanafuda! Nintendo Museum | Used for the 48-card, 12-month Hanafuda structure and Nintendo Museum workshop context. |
| naoj-2026-moon | Chushu no Meigetsu, September 2026 National Astronomical Observatory of Japan | Used for the 2026 date of Chushu no Meigetsu and the full-moon timing. |
| naoj-calendar-wiki | Meigetsu is not necessarily the full moon NAOJ Calendar Wiki | Used to cross-check Chushu no Meigetsu and full-moon separation across years. |
| cao-holidays-2026 | National Holidays for 2026 and 2027 Cabinet Office, Government of Japan | Used for Japan's September 2026 public holidays and holiday-law notes. |
| jnto-january | Japan in January Japan National Tourism Organization | Used for New Year travel framing, winter conditions, snow sports, illuminations, and hot spring context. |
| jnto-february | Japan in February Japan National Tourism Organization | Used for late-winter weather, snow festivals, winter sports, and early Okinawa cherry-blossom context. |
| jnto-march | Japan in March Japan National Tourism Organization | Used for Hinamatsuri, late plum blossom, early cherry blossom, and spring-weather framing. |
| jnto-april | Japan in April Japan National Tourism Organization | Used for sakura travel, Hirosaki Cherry Blossom Festival, and spring mountain-route context. |
| jnto-may | Japan in May Japan National Tourism Organization | Used for Golden Week, wisteria-viewing, late northern cherry blossom, and mild-weather framing. |
| jnto-june | Japan in June Japan National Tourism Organization | Used for rainy-season framing, minazuki wording, Hokkaido travel context, and Sapporo June festivals. |
| jnto-july | Japan in July Japan National Tourism Organization | Used for the post-rainy-season heat, summer travel activities, and July festival calendar context. |
| jnto-august | Japan in August Japan National Tourism Organization | Used for Obon, summer festivals, fireworks, Awa Odori, Aomori Nebuta, Sendai Tanabata, and Akita Kanto context. |
| jnto-september | Japan in September Japan National Tourism Organization | Used for seasonal travel/weather framing and September festival context. |
| jnto-october | Japan in October Japan National Tourism Organization | Used for autumn weather, harvest festivals, foliage timing, art travel, and October seasonal framing. |
| jnto-november | Japan in November Japan National Tourism Organization | Used for clear late-autumn weather, foliage, hot springs, winter illuminations, sumo, and Karatsu Kunchi context. |
| jnto-december | Japan in December Japan National Tourism Organization | Used for winter illumination, ski-season, first-snow, year-end, New Year's Eve, and Namahage context. |
| jnto-tsukimi | Tsukimi, Moon Viewing in Japan Japan National Tourism Organization | Used for contemporary Tsukimi practices, offerings, and seasonal framing. |
| jnto-momijigari | Momijigari: How to enjoy autumn in Japan Japan National Tourism Organization | Used for the meaning of momijigari, contemporary leaf-viewing outings, and autumn travel context. |
| jnto-koyo-history | History & Culture of Koyo Japan National Tourism Organization | Used for the history of autumn-leaf viewing and the deer-and-maple pairing in Japanese visual culture. |
| jnto-autumn-leaves | Autumn Leaves (Koyo) of Japan Japan National Tourism Organization | Used for the north-to-south progression of autumn color and contemporary viewing guidance. |
| visit-nara-autumn | Autumn in Nara: Where to See the Season's Best Colors Official Nara Travel Guide | Used for modern deer-and-foliage context around Nara Park. |
| kokugakuin-choyo | Choyo Kokugakuin University Digital Museum, Encyclopedia of Shinto | Used for Choyo no Sekku, chrysanthemum wine, and festival history. |
| ndl-choyo | Choyo-no-Sekku (Chrysanthemum Festival) National Diet Library Image Bank | Used for historical visual source leads related to Choyo no Sekku. |
| shungate-choyo | September 9, Choyo no Sekku SHUN GATE / Washoku Association of Japan interview | Used for food-culture context around Choyo no Sekku. |
| koikoi-cultural-reference | Cultural Reference - Hanafuda & the Twelve Months Koi-Koi repository | Internal topic map only; not treated as external factual authority. |
| koikoi-rules | Koi-Koi - Rules & Variants Koi-Koi repository | Used for the current Koi-Koi ruleset and house-rule disclosure. |
| koikoi-validation | Koi-Koi Validation Koi-Koi repository | Used for internal release-status and rules-validation context. |
| koikoi-app-store | Koi-Koi Apple App Store | Used for public App Store availability, platform, price, developer, and privacy-status checks. |
| japan-prefecture-geojson | open-data-jp-prefectures-geojson npm / piuccio | Used for the events map prefecture boundaries; the package is MIT licensed and based on National Land Information Division data. |
| iwate-chusonji-900-secret-buddha | Chuson-ji Temple 900th Anniversary of the Opening of the Secret Buddha Iwate Tourism Association | Used for the 2026 Chuson-ji anniversary event period, venue, and secret-Buddha opening context. |
| visit-hanamaki-hanamaki-festival-2026 | Hanamaki Festival Visit Hanamaki / Hanamaki City Tourism Division | Used for the 2026 Hanamaki Festival dates, scheduled hours, location, organizer, and festival components. |
| tourism-expo-japan-2026-outline | Outline | Tourism EXPO Japan 2026 Tourism EXPO Japan Promotion Office | Used for Tourism EXPO Japan 2026 dates, Tokyo Big Sight venue, trade/press and public-day split, and organizer information. |
| jnto-visit-japan-travel-mice-mart-2026 | VISIT JAPAN Travel & MICE Mart 2026 Japan National Tourism Organization | Used for VJTM 2026 dates, Tokyo Big Sight West Hall 1 venue, organizer, and Japan Tourism Agency support note. |
| kurume-kora-taisha-okunchi-2026 | Kora Taisha Shrine "Okunchi" Kurume City Official Tourism Guide | Used for Kora Taisha Shrine Okunchi 2026 dates, shrine venue, festival schedule notes, and Choyo timing context. |
| visit-kobe-minato-hanabi-2026 | MINATO HANABI Fireworks Festival VISIT KOBE - Official Travel Guide to Kobe | Used for MINATO HANABI 2026 dates, Meriken Park venue, nightly timing, admission note, and severe-weather caveat. |
| bunka-designated-cultural-property-counts | Designated Cultural Properties by Prefecture Agency for Cultural Affairs, Government of Japan | Used for prefecture-level National Treasure and Important Cultural Property sculpture-record counts. The Agency notes that Important Cultural Property counts include National Treasures. |
| kunishitei-national-cultural-property-database | Database of National Cultural Properties Agency for Cultural Affairs, Government of Japan | Used to confirm the official search categories and prefecture/classification basis for designated cultural properties. |
| gsi-area-survey-2026 | Municipal Area Survey of Japan, 2026 Geospatial Information Authority of Japan | Used for prefecture land-area denominators in density calculations, using the 2026-04-01 area survey. |
| bunka-religious-statistics | Religious Statistics Survey Agency for Cultural Affairs, Government of Japan | Reviewed as contextual national religious-landscape data; not used as a Buddha-count metric. |
| nara-cultural-property-counts | Nara Prefecture Cultural Property Count Nara Prefecture | Used as a prefectural cross-check and editorial context for Nara's concentration of National Treasure sculpture. |
| todaiji-daibutsuden | Daibutsuden Hall and the Great Buddha Tōdai-ji Temple | Used for the Tōdai-ji Great Buddha example and scale reference. |
| kotokuin-kamakura-daibutsu | The Great Buddha and Kotoku-in Kōtoku-in Temple | Used for the Kamakura Daibutsu example, designation, date and scale. |
| usuki-sekibutsu | Usuki Stone Buddhas Usuki Stone Buddhas | Used for the Usuki Stone Buddhas example, National Treasure status and more-than-60 figure context. |
| sanjusangendo-statues | Sanjūsangen-dō Statues Rengeō-in Sanjūsangen-dō | Used for the Kyoto Kannon figure group and National Treasure context. |
| byodoin-amida | Phoenix Hall and Amida Buddha Byōdō-in Temple | Used for the Byōdō-in Amida example and National Treasure context. |
| toji-mandala | Tō-ji 3D Mandala Tō-ji Temple | Used for the Kōdō sculptural mandala example and image-type distinctions. |
| nihonji-nokogiriyama | Nihon-ji, Nokogiriyama Nihon-ji Temple | Used for the Nokogiriyama Buddhist landscape example and access caveat. |
| visit-wakayama-koyasan | Kōya-san Wakayama Prefecture Tourism Federation | Used for Kōya-san temple-settlement and pilgrimage-landscape context. |
| shikoku-henro-official | Shikoku 88 Temple Pilgrimage Shikoku Tourism Creation Organization | Used for Shikoku Henro distance, temple count and route context. |
| bungotakada-kumano-magaibutsu | Kumano Magaibutsu Bungotakada City | Used for the Kumano cliff-carved Buddhist image example. |
| jaanus-magaibutsu | Magaibutsu Japanese Architecture and Art Net Users System | Used for the definition of magaibutsu and the broader rock-cut image context. |
| japan-castle-foundation-top-100 | Japan's Top 100 Castles Japan Castle Foundation | Used for the official identity, list number, list membership, location municipality, castle type, founding label, builders, principal lords, cultural-property notes, and keep-status notes for the original 100-castle selection. |
| japan-castle-foundation-continued-top-100 | Continued Top 100 Japanese Castles Japan Castle Foundation | Used for the official identity, list number, list membership, location municipality, castle type, founding label, builders, principal lords, and cultural-property notes for the continued 100-castle selection. |
| japan-castle-foundation-position-map | Japan's Top 100 and Continued Top 100 Castle Position Data Japan Castle Foundation / Nippon Castle | Used for the 200 castle addresses and coordinates exposed through the public map linked from the Japan Castle Foundation castle-search page. |
| wikipedia-english-castle-list-names | 100 Fine Castles of Japan and Continued 100 Fine Castles of Japan Wikipedia contributors | Used only as a secondary cross-check for common English castle names; Japan Castle Foundation records remain the corpus source of truth. |
| jnto-original-castles | Discover Japan's Twelve Original Castles Japan National Tourism Organization | Used as visitor-facing context for the surviving original-keep distinction, while individual list identity remains sourced to the Japan Castle Foundation. |
| unesco-himeji | Himeji-jo UNESCO World Heritage Centre | Used for Himeji Castle's World Heritage context. |
| unesco-historic-kyoto | Historic Monuments of Ancient Kyoto UNESCO World Heritage Centre | Used for Nijō Castle's World Heritage association within the Historic Monuments of Ancient Kyoto property. |
| unesco-ryukyu-gusuku | Gusuku Sites and Related Properties of the Kingdom of Ryukyu UNESCO World Heritage Centre | Used for Okinawa gusuku World Heritage context. |
| shuri-seiden-opening-2026 | Shuri Castle Seiden opening date announced (首里城正殿供用開始) Okinawa Commemorative National Government Park (Shuri Castle Park) | Completion ceremony on November 22, 2026 and public opening of the rebuilt main hall on November 23, 2026. |
| cmeg-castle-fields | Nippon Shiro Meguri castle records: keep structure, remains and rebuilt structures Nippon Shiro Meguri (cmeg.jp) | Structured fields for each of the 200 castles, used to classify what stands at each site today. The linked record for each castle is its coordinate source. |
| ikkoku-ichijo-rei | Ikkoku ichijō rei (一国一城令) Yamakawa Shuppansha, Historist glossary | The 1615 Tokugawa order limiting each domain to one castle. |
| shimane-haijorei | The Meiji government's castle abolition order (明治政府による「廃城令」) Shimane Prefectural Center for Ancient Culture | The 1873 order dividing castles between army use and disposal. |
| wartime-keep-losses | The seven castle keeps burned in the war (戦災で焼けた「7棟の天守」) Daily Shincho | The keeps destroyed by air raids and the atomic bombing in 1945. |
| kakegawa-wooden-keep | Kakegawa Castle keep 30th anniversary symposium (掛川城天守閣木造復元の歴史的意義) Kakegawa City | Kakegawa's 1994 keep, the first wooden keep rebuilt after the war. |
| kumamoto-castle-recovery | Kumamoto Castle Recovery Basic Plan, revised March 2023 (熊本城復旧基本計画) Kumamoto City | Recovery after the 2016 earthquakes, with full restoration planned by fiscal 2052. |
| nagoya-keep-project | Nagoya Castle keep project progress (天守閣整備事業の進捗情報) Nagoya Castle / City of Nagoya | The closed 1959 concrete keep and the plan to replace it with a wooden keep. |
| kagoshima-haibutsu-kishaku | Haibutsu kishaku (廃仏毀釈) in Kagoshima Kagoshima Prefecture | The domain's abolition of Buddhism after 1868: temples and Buddhist images destroyed, and for several years no temple or monk in the domain. |
| todaiji-history | History of Tōdai-ji Temple Tōdai-ji | The 743 proclamation, the 752 dedication, the 1180 fire and Chōgen's restoration. |
| todaiji-nandaimon | Nandaimon (Great South Gate) and the Kongō Rikishi Tōdai-ji | The guardian figures carved under Unkei and Kaikei in 69 days in 1203. |
| nagahama-kannon-no-sato | What is the Kannon no Sato? (観音の里とは) Nagahama Tourism Association | Village Kannon images hidden in riverbeds and underground during wartime burnings, and cared for by villagers today. |
| enkakuji-ruins | Enkaku-ji Temple Ruins (円覚寺跡) Agency for Cultural Affairs, Cultural Heritage Online | The Ryukyu royal temple founded in 1492, whose buildings were designated National Treasures in 1933 and destroyed in the Battle of Okinawa. |
| mext-koshaji-hozon-ho | Ancient Shrines and Temples Preservation Law of 1897 (古社寺保存法) Ministry of Education, Culture, Sports, Science and Technology | The 1897 law that first designated temple treasures as National Treasures. |
| yumedono-fenollosa | Excavating the Hall of Dreams: The Inventions of “Fine Art” and “Religion” in Japan Religions (MDPI), 2022 | Fenollosa and Okakura's 1884 survey at Hōryū-ji and the unwrapping of the Yumedono Kannon. |
| hls-2023-summary | 2023 Housing and Land Survey: summary of basic results (令和5年住宅・土地統計調査 住宅及び世帯に関する基本集計 結果の概要) Statistics Bureau of Japan | National totals, vacancy by type since 1978, detached-house vacancy, and the prefecture appendix used to check every prefecture rate. |
| hls-2023-table1 | 2023 Housing and Land Survey, main table 1: dwellings by occupancy status, Japan, prefectures and municipalities Statistics Bureau of Japan / e-Stat | Counts of total, vacant, idle, for-rent, for-sale and second-home dwellings for every prefecture and surveyed municipality. |
| popest-2023-age | Population Estimates as of 1 October 2023, table 3: population by age group and prefecture Statistics Bureau of Japan | Used to calculate each prefecture's share of residents aged 65 and over. |
| census-2020-basic | 2020 Population Census, basic complete tabulation: summary of results, table I-2-1 Statistics Bureau of Japan | Prefecture population change between the 2015 and 2020 censuses. |
| mlit-akiya-owner-survey-2024 | 2024 Survey of Vacant House Owners (令和6年空き家所有者実態調査) Ministry of Land, Infrastructure, Transport and Tourism | How owners acquired vacant homes, why they became vacant, building age, condition, planning before inheritance and owners' intentions. Published August 29, 2025. |
| mlit-vacant-houses-act-2023 | Amended Act on Special Measures Concerning the Promotion of Measures for Vacant Houses (空家等対策の推進に関する特別措置法) Ministry of Land, Infrastructure, Transport and Tourism | The 2023 amendment, in force from December 13, 2023, including the new category of poorly managed vacant houses. |
| moj-inheritance-registration-2024 | Mandatory Inheritance Registration (from April 1, 2024) Ministry of Justice | Heirs must register inherited land and buildings within three years of learning of the inheritance. |