検索 · THE OPEN ARCHIVE
1,920 long-form SERP analyses, continuously maintained since 2019 — the working record of how search actually behaves in Japan.
Every dispatch in this library was written by our Tokyo-based analyst team, drawn from a daily tracking set of more than 1.8 million keywords across Google.co.jp and Yahoo! JAPAN. Filter by vertical, scan the recent dispatches, or open the briefs that have shaped how Japan-market SEO teams plan their next quarter.
Read by SEO teams at Mercari, Rakuten Group, Recruit, Sony Network Communications, and LINE — average weekly open rate of 47%.
分類 · FIVE RESEARCH VERTICALS
The library is organized around the questions a Japan-targeting SEO actually asks.
Each vertical below is a curated set of long-form analyses. Every entry carries the data set used, the methodology, and the date the SERP was sampled — written to be re-cited, not skimmed.
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01
Algorithm Updates on Google.co.jp
Confirmed and suspected core updates, Helpful Content refinements, and the ranking shifts Japanese publishers actually felt.
Read recent dispatches → -
02
Yahoo! JAPAN Search Behaviour
Market share shifts, the Yahoo! vs. Google divide by vertical, and the ad-load / organic overlap that keeps changing quarter to quarter.
Read recent dispatches → -
03
Vertical SERP Features
How the SERP itself changes by industry: finance, travel, recipe, medical, and the local pack behavior in Japanese metros.
Read recent dispatches → -
04
E-commerce SERP Mechanics
Product carousel triggers, merchant listing behavior on Google.co.jp and Yahoo! Shopping, and how price-comparison SERPs cannibalize organic.
Read recent dispatches →
A fifth vertical — Localization & Cross-border SERP demand — carries the remaining 512 entries and is surfaced through the global search bar at the top of the page.
抜粋 · RECENT DISPATCHES
Four analyses that have been most cited by Japan-market SEO teams in the past 12 months.
Pulled from the archive by editors, not algorithms — the entries below are the ones our subscribers forwarded, screenshotted, and re-cited in their own Q4 and Q1 planning documents.
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The December 2024 Helpful Content refinement hit Japanese affiliate SERPs 3.1× harder than publisher SERPs.
We tracked 41,200 affiliate and 38,600 publisher URLs across 30 verticals. After the December 2024 HCU refinement, affiliate SERPs lost 22.7% of their first-page positions on average, while publisher SERPs fell 7.4%. The dispersion was concentrated in insurance, credit-card, and VPN keywords — three verticals where aggregator content tends to dominate the pre-update SERP.
Finding. Affiliate SERP exposure to HCU is not uniform; it tracks closely with E-E-A-T signals on author pages and outbound citation density. Sites that lost the most had an average of 4.2 author bios per 100 articles against the surviving-set average of 19.6.
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Yahoo! JAPAN's organic share crossed 11% in Q4 2024 — and it is no longer concentrated in older demographics.
Using Similarweb's Japan-market panel and our own 1.8M-keyword daily tracking, we segmented Yahoo! JAPAN's organic share by device and age. The persistent assumption that Yahoo! JAPAN is the SERP of users over 50 only holds for one vertical: finance. In shopping, recipes, and entertainment, the platform's age distribution now mirrors Google.co.jp's, with 31% of Yahoo! JAPAN sessions coming from users under 35.
Finding. Yahoo! JAPAN's organic share growth in 2024 was driven by younger users in vertical categories that Google treats as commercial. Brands optimizing exclusively for Google.co.jp in retail and recipe are leaving 7–14% of qualified organic sessions unaddressed.
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Recipe SERPs in Japan are now 71% image-driven on mobile — and recipe blogs without structured ingredient markup are being pushed below the carousel.
We sampled 1,200 recipe queries on Google.co.jp mobile and parsed the top-10 results by element: image pack, video carousel, structured snippet, organic link. Image-driven layouts account for 71% of recipe SERPs, up from 49% in 2022. Pages without structured ingredient markup were demoted to position 8 or lower 62% of the time.
Finding. Adding structured ingredient markup moved test pages up an average of 2.4 positions in recipe SERPs within 18 days. The same test on desktop SERPs produced no measurable movement.
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Merchant listing concentration on Google.co.jp: 64% of product carousel slots go to four platforms — and the long tail of Rakuten merchants is being squeezed.
Across 2,400 product queries in seven categories, the Google product carousel on Google.co.jp sourced 64% of slots from Amazon Japan, Mercari, Yahoo! Shopping, and a single major comparison engine. Rakuten-origin product listings — historically a meaningful presence on Japanese product SERPs — fell to 8.2% of carousel slots, down from 21% in 2021.
Finding. For merchants whose primary Japanese sales channel is direct SEO to a product detail page, the SERP is now functionally a four-horse race. Diversification into comparison engines and merchant feeds has become a baseline requirement, not an optimization.
The full archive contains 1,920 entries. Subscribers to the weekly brief receive each new dispatch the morning it is filed.
引用 · THIRD-PARTY CITATIONS
Ranking Japan's research has been cited and referenced by named Japan-market publications and industry stages.
The library is not just read on our own channels — findings, data series, and the JP-SERP Volatility Index have surfaced in external reporting and on professional stages.
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Nikkei Digital Gear
Cited our JP-SERP Volatility Index in its 2024 Japan search trends report — the first independent third-party use of the proprietary data series.
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ITmedia Marketing
Referenced our Yahoo! JAPAN vs. Google.co.jp market-share series in a 2024 long-read on Japan's bifurcated search market.
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Web担当者Forum
Quoted our December 2024 Helpful Content refinement analysis in its affiliate-SERP coverage for in-house marketing teams.
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BrightEdge Japan Summit
Featured speaker in 2023 and 2024 — data talks presented original research from the archive to attending enterprise SEO teams.
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Asia Search Awards 2023
Winner, "Best Use of Search in Publishing" — Independent Category, recognizing the publication's research depth and citation reach.
順位
"Across the 1.84M Japanese keywords we track daily, organic position-1 volatility on Google.co.jp now exceeds 3.1× the trailing-five-year median on any given algorithm-refinement week — and the cadence of those weeks has shortened from 11.4 weeks in 2020 to 3.2 weeks in 2024."
The cadence collapse — long quiet stretches punctuated by recovery periods — is the single most useful leading indicator for Japan's enterprise SEO teams in 2025.
THE WEEKLY BRIEF
Get the next dispatch from the archive's authors, in your inbox each Tuesday.
The same analyst team that has produced every entry in this library — twelve full-time researchers based in Tokyo and Osaka — files a single Sharp, data-forward brief each week. Average open rate: 47% against a 21% industry benchmark.
Read by SEO teams at Mercari, Rakuten Group, Recruit, Sony Network Communications, and LINE.