Japan Court Auction (BIT) Scraper — Foreclosure Listings

Scrapes Japan's official court auction database, BIT (不動産競売物件情報サイト), operated by the Supreme Court of Japan. Covers all 50 district courts across all 47 prefectures and extracts structured listing data including case numbers, addresses, bid prices, deadlines, and optional 3-point-set PDF links.

What BIT Is

BIT is the official public database for court-ordered foreclosure auctions in Japan. Properties are sold through a transparent bidding process administered by district courts. Listings typically appear at 60–80% of appraised value — making them attractive to investors, real estate professionals, and due-diligence researchers. Each listing is accompanied by a 3-point-set PDF bundle (物件明細書, 現況調査報告書, 評価書) containing title details, current status, and valuation reports.

What This Actor Extracts

For each foreclosure listing:

Field	Description
case_number	Court case number (事件番号), e.g. 令和07年(ケ)第270号
court_name	District court name
court_branch	Branch name (支部); empty for main court
prefecture	Prefecture slug (e.g. tokyo, osaka)
city	City / ward / town
address_ja	Full Japanese address
postal_code	7-digit postal code
latitude / longitude	Geocoordinates from map embed
property_type	land / house / land_house / mansion_unit / apartment / other
land_area_sqm	Land area in m²
building_area_sqm	Building floor area in m²
building_year	Year constructed
building_age_years	Building age in years
building_structure	Structure type (木造, RC, 鉄骨, etc.)
floors	Number of floors
rooms_layout	Room layout, e.g. 3LDK
zoning	Zoning classification
min_sale_price_jpy	Reserve price 売却基準価額 (JPY)
min_bid_price_jpy	Minimum bid 買受可能価額 (JPY)
deposit_required_jpy	Required deposit 買受申出保証金 (JPY)
bid_period_start	Bid window start (YYYY-MM-DD)
bid_period_end	Bid window end (YYYY-MM-DD)
opening_date	Announcement date 開札期日 (YYYY-MM-DD)
sale_round	Auction round (1 = first, 2 = special sale)
occupancy_status	vacant / tenanted / owner_occupied / unknown
three_point_set_url	URL for 3-point-set PDF bundle
photos	Listing photo URLs (pipe-separated)
listing_url	Direct URL to BIT detail page
scraped_at	Scrape timestamp (ISO 8601 UTC)

Input Parameters

Parameter	Type	Description
prefectures	array	Prefecture slugs to scrape (tokyo, osaka, etc.). Empty = all 47.
maxItems	integer	Maximum results. 0 = unlimited.
downloadThreePointSet	boolean	Download and summarize 3-point-set PDFs. Slower but extracts occupancy, defects, and valuation detail.
proxyConfiguration	object	Proxy settings. JP residential proxy recommended.

Prefecture Slugs

All 47 prefectures are supported: hokkaido, aomori, iwate, miyagi, akita, yamagata, fukushima, ibaraki, tochigi, gunma, saitama, chiba, tokyo, kanagawa, niigata, toyama, ishikawa, fukui, yamanashi, nagano, gifu, shizuoka, aichi, mie, shiga, kyoto, osaka, hyogo, nara, wakayama, tottori, shimane, okayama, hiroshima, yamaguchi, tokushima, kagawa, ehime, kochi, fukuoka, saga, nagasaki, kumamoto, oita, miyazaki, kagoshima, okinawa.

Example Output

{
  "case_number": "令和07年(ケ)第270号",
  "court_name": "東京地方裁判所",
  "court_branch": "",
  "prefecture": "tokyo",
  "city": "目黒区",
  "address_ja": "東京都目黒区中町二丁目",
  "postal_code": "153-0065",
  "latitude": 35.632,
  "longitude": 139.693,
  "property_type": "mansion_unit",
  "land_area_sqm": null,
  "building_area_sqm": 58.32,
  "building_age_years": 28,
  "building_year": 1997,
  "building_structure": "鉄筋コンクリート造",
  "floors": 14,
  "rooms_layout": "2LDK",
  "zoning": "第一種住居地域",
  "min_sale_price_jpy": 32000000,
  "min_bid_price_jpy": 25600000,
  "deposit_required_jpy": 6400000,
  "bid_period_start": "2026-05-12",
  "bid_period_end": "2026-05-19",
  "opening_date": "2026-05-26",
  "sale_round": 1,
  "occupancy_status": "vacant",
  "three_point_set_url": "https://www.bit.courts.go.jp/app/detail/pd001/h04?courtId=31111&saleUnitId=00001234567",
  "photos": "https://www.bit.courts.go.jp/data/image/...",
  "listing_url": "https://www.bit.courts.go.jp/app/propertyresult/pr001/h05?saleUnitId=00001234567&courtId=31111",
  "scraped_at": "2026-05-18T10:00:00.000Z"
}

How It Works

1. Fetches the BIT schedule index listing all district courts
2. Filters courts by requested prefectures (using the court ID to prefecture mapping embedded in the index)
3. For each court, reads the upcoming auction schedule
4. POSTs to the results listing endpoint for each scheduled auction period
5. Fetches the full detail page for each listing
6. Optionally checks the 3-point-set PDF availability

The actor uses a residential Japanese IP proxy to ensure reliable access to the government server. Rate limiting (300ms between GET requests, 800ms between POST requests) prevents overloading the court system.

Notes

• BIT only lists active auctions — concluded sales and historical data are not available
• Some listings appear multiple times with different case_number entries when a case has multiple properties
• sale_round: 2 indicates a "special sale" (特別売却) — a second-chance auction at a lower price
• The 3-point-set PDFs require a separate download session; set downloadThreePointSet: true for occupancy and defect details
• Japanese dates (和暦 era dates) are automatically converted to Gregorian (YYYY-MM-DD)
• Dates are 和暦 on the BIT pages: 令和 = 2018+year, 平成 = 1988+year, 昭和 = 1925+year