• 2026-03-19 V4.9.0 Added Testimony Files page for audio content listings. Removed floating audio button and added header/footer navigation links. Added SSD MVP link to development diagnostic page and SSD Genba Kaizen link to waste diagnostic page. Unified DiagnosticCards sponsor link to playground.style/ssd
• 2026-03-19 V4.8.0 Added brand sections to home page — Rules of Investigation, Three Philosophies, and Investigation Method. Redesigned contact section as a two-step flow: Step 1 (diagnostic baseline) → Step 2 (investigation request), removing forms from the home page and funneling through diagnostics. Replaced service banner with Sponsored by Playground Inc. (SSD) sponsor display
• 2026-03-17 V4.7.0 Full English localization of all 8 diagnostics (7 individual + comprehensive report). Added personalized "next steps" action section to results. Updated share copy to encourage sharing actionable insights. Added sepia-toned hero images to each diagnostic LP. Converted key-person risk assessment to USD for English users. Enabled language toggle on partner pages
• 2026-03-16 V4.6.0 Refreshed diagnostic section from dark theme to white background with orange and blue accents. Moved diagnostic widget to top of page and diagnostic links right after for Google Ads traffic. Reordered top page sections to Learning → Diagnostics → Tools → Reports. Added Playground Genba Kaizen support service link to all diagnostic LPs
• 2026-03-13 V4.5.0 Added CASE FILE #006 DX Readiness Assessment and #007 IT Health Check (7 questions each, 0-100 score). Added #006 and #007 links to header, footer, and diagnostic cards
• 2026-03-13 V4.4.0 Added CASE FILE #005 Knowledge Sharing Assessment (7 questions, 0-100 score). Unified diagnostics section across all LPs with shared DiagnosticCards component. Added CASE FILE numbers to hero sections. Changed mobile assistant button to icon-only. Fixed Slack notification score display by diagnostic type
• 2026-03-12 V4.3.0 Redesigned all partner pages as diagnostic-first LPs. Added 4 risk diagnostics: CASE FILE #001–#004 (Key-Person Risk, System Development Risk, Business Efficiency Risk, 7+1 Waste). Unified at 7 questions each (7+1 for Waste). GTM integration, SNS sharing, and backend submission included. Added CASE FILE numbering to header and footer navigation
• 2026-03-12 V4.2.1 Added ROI Detective Assistant widget to partner pages (external link on mobile). Shortened language toggle to JA/EN and improved mobile header layout
• 2026-03-03 V4.2.0 Added new service "KOE-Score" (AI-powered review analytics tool)
• 2026-03-02 V4.1.0 Auto-create tentative Google Calendar events on consultation booking to prevent double-booking. Admin confirmation deletes tentative events and creates confirmed events. Renamed "Micro-SaaS" to "Micro-System"
• 2026-02-27 V4.0.0 Added Sherlock Holmes quote to home hero. Added section scroll navigation to Detective Tools page. New signup landing page explaining membership benefits and registration flow. New Members page. Reorganized footer into 4 sections. Unified "Dev" and "SaaS" terminology to "Detective Tools" for world-building consistency
• 2026-02-27 V3.9.0 Randomized quiz question and choice order. Added SNS links (X, Instagram, Facebook, LinkedIn) and comment field to profile. New Detective Ranking page with accuracy, badges, and profile info
• 2026-02-26 V3.8.0 Added avatar image upload to profile. New quiz progress and badge system (6 badge types). Introduced gold-framed owner icon
• 2026-02-26 V3.7.0 Added comprehension quiz feature to Classified Files (48 articles, 5 questions each). Google authentication via Firebase Auth, nickname settings, per-article and overall rankings, and profile page
• 2026-02-24 V3.6.0 Added Micro-System Builder partner landing page. Replaced service card images with videos
• 2026-02-24 V3.5.0 Added business case report form and consultation booking at the end of article pages (Japanese only). Added admin page for scheduling Zoom consultations with email confirmation
• 2026-02-21 V3.4.0 Added site feedback feature to footer (5-star rating, message, and thank-you email)
• 2026-02-19 V3.3.0 Added tag-based service banners to articles (SWOT/PEST/3C → Strategic ROI Intelligence, ICE/RICE/KANO → Proposal Generator)
• 2026-02-17 V3.2.0 Added "321 Platform" service card to home page
• 2026-02-17 V3.1.0 Added "321 Platform" to services
• 2026-02-16 V3.0.0 Migrated to Astro SSG — all pages now statically generated for improved SEO and page load speed
• 2026-02-16 Changed URL structure to /ja/, /en/ path prefixes (old URLs auto-redirect)
• 2026-02-16 Sitemap now auto-generated with hreflang support
• 2026-02-15 V2.3.0 Added new service "Strategic ROI Intelligence" (AI-powered PEST, SWOT & 3C analysis tool)
• 2026-02-14 V2.2.0 Added SNS links (X, LinkedIn, Instagram, Product Hunt) to footer
• 2026-02-14 Added English/Japanese switching for meta title and description
• 2026-02-14 Fixed Twitter OGP not displaying
• 2026-02-14 Added environment variable validation to deploy.sh
• 2026-02-14 Separated .env files into local and production
• 2026-02-12 V2.1.0 Added related links to footer
• 2026-02-12 Created release notes page
• 2026-02-12 Added feedback feature to article pages (with Slack notification)
• 2026-02-12 Added Google ad between 1st and 2nd items in Case Files and Classified Files lists
• 2026-02-12 Created privacy policy page
• 2026-02-02 V2.0.0 ROI Detective Agency renewal
• 2026-01-23 V1.7.1 Added navigation cards for learning content and services
• 2025-12-23 V1.7.0 Added article links to Classified Files
• 2025-12-21 V1.6.7 Added business framework "ECRS" to Classified Files
• 2025-12-20 V1.6.6 Added business frameworks "CAGE" and "STP" to Classified Files
• 2025-12-15 V1.6.5 Added business framework "RICE" to Classified Files
• 2025-12-12 V1.6.4 Added business framework "RFP" to Classified Files
• 2025-11-07 V1.6.3 Added Gemini analysis report to Reports page
• 2025-11-06 V1.6.2 Published 300 Case File articles
• 2025-11-04 V1.6.1 Added business framework "Persona Analysis" to Classified Files
• 2025-10-27 V1.6.0 Added business framework "ICE Scoring" to Classified Files
• 2025-10-24 V1.5.9 Added related files to Case File articles
• 2025-10-20 V1.5.8 Added business framework "Kano Model" to Classified Files
• 2025-10-20 V1.5.7 Added business framework "BOM" to Classified Files
• 2025-10-20 V1.5.6 Added business framework "NPS" to Classified Files
• 2025-10-07 V1.5.5 Added social share buttons "LinkedIn" and "Facebook" to Classified Files and Case Files
• 2025-10-06 V1.5.4 Added business framework "HEART" to Classified Files
• 2025-10-02 V1.5.3 Added business framework "Agile Development" to Classified Files
• 2025-09-30 V1.5.2 Added business frameworks "MVP" and "Implementation First Principle" to Classified Files
• 2025-09-25 V1.5.1 Added 6D Matrix business framework to Classified Files
• 2025-09-22 V1.5.0 Added Blue Ocean Strategy business framework to Classified Files
• 2025-09-17 Translation rewrite up to Episode 200
• 2025-09-17 Published 200 Case File articles
• 2025-09-16 V1.4.9 Added Scene Cast Theory business framework to Classified Files
• 2025-09-11 V1.4.8 Added Double Diamond and Design Thinking business frameworks to Classified Files
• 2025-09-10 V1.4.7 Added Jobs-to-be-Done Theory and OKR business frameworks to Classified Files
• 2025-09-08 V1.4.6 Added RCD business framework to Classified Files
• 2025-09-05 V1.4.5 Added OODA business framework to Classified Files
• 2025-09-02 V1.4.4 Split Case Files and Classified Files rankings on Ranking page
• 2025-08-22 V1.4.3 Added 8 data analysis books by ROI Detective to Ranking page
• 2025-08-02 V1.4.2 Added ads and trends for Indian and Japanese audiences to Reports page
• 2025-07-29 Produced up to Episode 100 of Case Files
• 2025-07-29 Translation rewrite up to Episode 100
• 2025-07-28 V1.4.1 Added device-type charts to Reports page
• 2025-07-27 V1.4.0 Added Ranking page to menu tabs
• 2025-07-26 V1.3.4 Added repeat user charts to Reports page
• 2025-07-26 V1.3.3 Added per-user and per-pageview AdSense revenue charts to Reports page
• 2025-07-20 V1.3.2 Added breadcrumb navigation to header
• 2025-07-19 V1.3.1 Added like button to Case Files and Classified Files
• 2025-07-18 V1.3.0 Optimized mobile browsing UX
• 2025-07-13 V1.2.0 Added screen views to Case Files and Classified Files
• 2025-07-11 V1.1.0 Added visitor count to Data Analysis LP
• 2025-07-11 V1.0.0 Added system version to footer
• 2025-07-08 Launched Data Analysis LP
• 2025-07-05 Added moving average to Reports page charts
• 2025-07-04 Added daily top 3 ranking to Classified Files
• 2025-06-29 Added Reports page to header navigation
• 2025-06-29 Added reading time to article pages
• 2025-06-27 Added Google AdSense revenue chart
• 2025-06-26 Added business frameworks X014–X026 to Classified Files
• 2025-06-22 Added latest news to top of article pages
• 2025-06-22 Published English edition of "The Irresponsibility Conspiracy" on Kindle
• 2025-06-21 Published Japanese edition of "The Irresponsibility Conspiracy" on Kindle
• 2025-06-16 Added trendlines to active user and pageview charts
• 2025-06-16 50 Markdown articles published
• 2025-06-16 Translation rewrite up to Episode 50
• 2025-06-15 Added active user chart to Roadmap page
• 2025-06-15 Added pageview chart to Roadmap page
• 2025-06-14 Automated weekly ranking display using GA4 view counts
• 2025-06-14 Added New icon for articles posted within 24 hours
• 2025-06-13 Added pagination to Case Files
• 2025-06-13 Added thumbnail images to Case Files
• 2025-06-09 Translation rewrite up to Episode 30
• 2025-06-09 Translation rewrite up to Episode 10
• 2025-06-08 Created top page
• 2025-06-07 Added SNS icon buttons to footer
• 2025-06-07 Launched Classified Files
• 2025-06-07 Published Privacy Policy
• 2025-06-07 Published Sitemap
• 2025-06-07 Published Roadmap
• 2025-06-03 Published Member Profiles
• 2025-06-02 Launched English site pages
• 2025-06-02 Added English/Japanese toggle button
• 2025-06-02 Published first English page
• 2025-06-02 Added global language support
• 2025-06-01 Set up Google AdSense
• 2025-05-30 Applied for Google AdSense
• 2025-05-30 Enhanced profiles and detective imagery
• 2025-05-30 Set up Slack notification for contact form submissions
• 2025-05-27 30 Markdown articles published
• 2025-05-24 Added tag filtering feature
• 2025-05-12 Added contact form (CTA enhancement)
• 2025-05-07 10 Markdown articles published
• 2025-05-04 Added internal links (previous/next article)
• 2025-05-04 Added sitemap.html
• 2025-05-03 Added description tags, updated sitemap.xml
• 2025-05-01 Developed ROI quick simulator
• 2025-04-30 5 Markdown articles published
• 2025-04-30 Event tracking via Google Tag Manager (GTM)
• 2025-04-28 Introduced Google Analytics 4 (GA4)
• 2025-04-27 Added SNS (X) share button to articles
• 2025-04-26 Published roadmap
• 2025-04-26 Added back-to-top button
• 2025-04-25 Enhanced SEO with title, tag, and OGP optimization
• 2025-04-25 Stabilized SEO with automatic sitemap.xml updates
• 2025-04-25 OGP and SEO support
• 2025-04-25 Automatic sitemap.xml generation
• 2025-04-25 OGP card display successful (SNS integration ready)
• 2025-04-25 Created X (formerly Twitter) account
• 2025-04-24 Responsive design implementation
• 2025-04-24 Site launch and deployment
• 2025-04-23 Built Markdown article viewer