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LegalAgent AI Legal Lab

AI Legal Lab

A media by legal professionals, for legal professionals, gathering the information needed to put legal AI to full use in everyday legal work.

Data Breach & Cyberattack News

See all listed incidents

Based on official announcements by companies and organizations in Japan.As of October 11, 2026

Listed incidents in numbers

Listed incidents
115 incidents
Incidents with confirmed leaks
49 incidents
Possible leaks / investigations
59 incidents
Incidents with service / business outages
32 incidents

Gross counts of exposed information

Reference sums excluding image metadata

Information confirmed exposed
Approx. 111,837,182 reported items
Information potentially exposed
Approx. 44,545,476 reported items

Including image metadata

Information confirmed exposed
Approx. 778,237,182 reported items
Information potentially exposed
Approx. 44,545,476 reported items
Breakdown and sources

Listed incidents by month

By the latest announcement listed for each incident

  1. Apr 20262
  2. May 20266
  3. Jun 202611
  4. Jul 202610
  5. Aug 202613
  6. Sep 202630
  7. Oct 202643

  1. Fourth report

    Under investigation

    IDC Frontier

    495 customer companies and public bodies

  2. Leak confirmed

    BOOKOFF Group Holdings

    Up to about 6.43 million membership-number records

  3. Leak confirmed

    dip

    Up to 3,885,771 records

  4. Leak confirmed

    Adventureskyticket: servers

    About 14.64 million records

  5. Leak confirmed

    Commune

    About 307,000 members (estimated)

Methods and coverage

See all listed incidents

Latest articles

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  1. Contract Review

    Worker Dispatch and Disguised Contracting: When the Worker Dispatch Act Applies Even Though the Contract Says "Outsourcing"

    6 min
  2. Contract Review

    Recruitment Agency Agreement Checkpoints: Placement Fees, Refunds and Direct-Hire Clauses

    6 min
  3. Contract Review

    Reviewing an Office Lease: Termination, Restoration and Deposit Deductions to Check Before Relocating

    8 min
  4. Contract Review

    Construction Subcontracts and the Construction Business Act: Written Contracts, the Ban on Bulk Subcontracting and Payment Deadlines

    6 min
  5. M&A Legal

    LBO Loan Term Sheets: Covenants and Events of Default That Shape Post-Acquisition Management

    13 min
  6. M&A Legal

    LBO Loan Security and Guarantees: The Timing of Providing the Target Company's Assets and Directors' Liability

    12 min
  7. Fundraising and Investment Agreements

    VC and CVC Fund Formation: Key Clauses of the Investment Limited Partnership Agreement and the Specially Permitted Business Notification

    22 min
  8. Startup Legal

    How a Company Should Respond to a Request for Collective Bargaining: Community Unions, the Duty to Bargain in Good Faith and Collective Agreements

    18 min
  9. Legal Outsourcing

    Tax Audits and Appeals Against Reassessments: Deadlines for Requests for Reinvestigation, Requests for Reconsideration and Tax Litigation

    21 min
  10. Contract Review

    Internal Use and Copyright: What to Check When Sharing Articles, Preparing Training Materials, and Using AI Summaries

    9 min

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Generative AI news

See all generative AI news

Each item links to its source.

  1. United States / AI & safety

    Anthropic reports unintended Claude actions on real websites during evaluations and internal use

    View primary source: Anthropic (official) (Open external link)

  2. Global / AI & developers

    Claude Managed Agents adds dynamic workflows in beta

    View primary source: Anthropic (official) (Open external link)

  3. United States / AI & developer tools

    Claude Code 2.1.296 fixes managed hook enforcement and edits to Shift-JIS files

    View primary source: Anthropic / GitHub (Open external link)

  4. China / AI & models

    Qwen releases Qwen-Image-2.1-Turbo, an eight-step image model under a research-only licence

    View primary source: Qwen (Open external link)

  5. China / AI & models

    Tencent releases Youtu-Parsing-Omni, a 5B model that parses documents, audio and video into JSON

    View primary source: Tencent (Open external link)

  6. Global / AI & enterprise use

    Sophos uses OpenAI Daybreak agents to shorten threat investigations

    View primary source: OpenAI (Open external link)

See all generative AI news

Topics

Contract Review108 related articles

108 related articles

Contract review playbooks, clause-level checkpoints, and practical review workflows.

  1. Legal Issues in Vertical Short Dramas: Performer Agreements, Secondary Use and Overseas Distribution

    14 min

  2. English-Language Contracts for Overseas Expansion: Choosing the Governing Law and Seat of Arbitration, and Provisions Your Team Can Operate

    5 min

  3. Carbon Credits and GX Initiatives: Regulation of Environmental Claims and Points to Check in Purchase Agreements

    6 min

  4. Change of Control Clauses: Points to Check for M&A, Capital Policy and Continuity of Business Relationships

    4 min

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Fundraising and Investment Agreements44 related articles

44 related articles

Startup financing topics including J-KISS, investment agreements, shareholders agreements, preferred shares, stock options, and capitalization.

  1. Trust-Type vs. Paid Stock Options: Taxation and Issuance Procedures

    15 min

  2. Convertible Notes vs. J-KISS: Repayment Obligations, Maturity and Conversion Terms

    15 min

  3. Startup Articles of Incorporation and Corporate Governance Structure: Provisions to Revisit When Raising Capital and How They Divide Roles with the Shareholders' Agreement

    15 min

  4. J-KISS Conversion (Exercise) Procedures: A Practical Guide to Avoid Scrambling at Series A

    15 min

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M&A Legal40 related articles

40 related articles

M&A legal work including legal due diligence, SPA review, representations, indemnities, closing, business transfers, and sell-side preparation.

  1. What Are Key Person Clauses and Retention? Closing Conditions and Measures to Keep People

    9 min

  2. What Is an Earn-Out Clause? A Mechanism for Bridging Valuation Gaps in M&A and Its Dispute Risks

    12 min

  3. What Is W&I Insurance (Representations and Warranties Insurance)? Risks Covered in M&A and the Seller's Liability

    8 min

  4. How to Choose an M&A Structure: A Legal Perspective for Narrowing Down Share Acquisitions, Business Acquisitions and Reorganizations

    12 min

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Law Changes Calendar

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The effective-date schedule of Japanese law changes affecting corporate practice, with effective dates, outlines and the businesses affected. The next scheduled changes are below.

Effective dateOutline and scope
2026.10.01–12.02 (by region)Revision of regional minimum wages (FY2026)Labor & HR / Businesses that employ workers
Export Trade Control Order amendment (additional export ban on Russia)Foreign exchange & export control / Businesses and trading companies that export goods to Russia
Shift of the consumption tax exemption system to a refund model (tax-free shop system)Tax & retail / Retailers operating tax-free shops (export goods sales sites)
2026.11.01 (planned)Amendment to the Logistics Efficiency Act (relay transport)Logistics & business regulation / Logistics operators conducting relay transport and operators of relay transport facilities

See all law changes

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What is AI Legal Lab?

LegalAgent AI Legal Lab is a media site that explains, as clearly as possible, how to put generative AI to work in everyday corporate legal practice.

As a law firm for the generative-AI era that already uses generative AI to the fullest in real legal work, Legal Agent shares its hands-on know-how and practical methods in plain language.

Media coverage

  1. Representative Attorney Asato contributed an article to the September 2026 issue of Kaisha Homu A2Z (Japanese) (Open external link)
  2. Representative Attorney Asato was featured in a NewsPicks special report (Japanese) (Open external link)
  3. Representative Attorney Asato and the AI Legal Lab were featured in Houritsushoku.com's "Law x AI" roundup (Japanese) (Open external link)