Corporate LawLast updated: 2026-05-034 min readLawyer-Reviewed

Japan Law Changes in May 2026: Complete Roundup of New Statutes Taking Effect

Key Takeaways

  • ✓A wave of significant legal reforms took effect in Japan between April and May 2026, covering family law, labor law, traffic, and corporate compliance
  • ✓Companies must urgently review HR policies for customer-harassment prevention, parental leave, and electronic bookkeeping mandates
  • ✓Individuals are affected by new bicycle traffic tickets, residential 30 km/h speed limits, and the criminalization of cannabis use
  • ✓Ongoing developments include same-sex marriage Supreme Court litigation and retrial system reform — both expected to evolve significantly through 2026

Not sure how this applies to your situation? Ask a lawyer — the first 30 minutes are free.

Share this article

A Major Inflection Point for Japanese Law

The April–May 2026 window has brought one of the largest waves of statutory reform in Japan's postwar history. This article catalogs the major laws taking effect (or whose enforcement is imminent) and outlines key compliance points across family, labor, traffic, corporate, and criminal law.

1. Family Law

Joint Custody Now Operational (Civil Code reform, effective April 1, 2026)

Japan's revised Civil Code (Act No. 33 of 2024) introduced opt-in joint custody after divorce. One month into enforcement, family courts are already seeing a sharp rise in joint-custody related mediation filings.

Key provisions include mandatory sole custody where domestic violence is present, and a new statutory child support floor of ¥20,000 per child per month.

Free Tool Related to This Article

Contract Risk Checker

Try our free simulator related to this topic.

Try for free →

2. Labor Law

Customer Harassment Prevention Mandate (effective October 2026)

Amendments to the Comprehensive Labor Policy Promotion Act will require all employers to implement customer-harassment prevention measures. Many large companies are already revising HR rules and response manuals during the lead-up.

Childcare and Family-Care Leave Act (effective April 1, 2026)

Employers must offer flexible work arrangements (shortened hours, telework) to employees raising children under three.

Removal of the "¥1.06M Wall"

The income threshold above which short-hour workers must enroll in social insurance is being phased out, with significant cost implications for retail, food service, and other industries with many part-time staff.

Freelance Protection Act — One Year In

After 18 months in force, administrative guidance is now being issued for violations of the written-terms requirement and 60-day payment rule. Hiring companies should re-audit their contracts.

3. Traffic and Road Safety

Bicycle "Blue Ticket" System (effective April 1, 2026)

Cyclists aged 16+ are now subject to traffic-infraction tickets, with fines ranging from ¥5,000 to ¥12,000 for offenses such as red-light running, phone use, and cycling under the influence. The National Police Agency reports approximately 8,000 tickets nationwide in the first month.

30 km/h Default Limit on Residential Roads

Local roads without center lines now have a statutory maximum speed of 30 km/h. Fleet operators must update driver guidance.

New "Standard Moped" Class

Motorcycles between 51cc and 125cc can now be operated under a moped license if they meet new performance restrictions, expanding rider options.

4. Corporate Compliance

Electronic Bookkeeping Mandate Fully Operational

Grace periods for the electronic preservation of digital transaction records have ended. Continuing to rely on paper or non-compliant electronic storage exposes companies to revocation of the blue tax return privilege and back taxes.

Invoice System Year Two (October 2026)

The transitional 80% input-tax credit for purchases from tax-exempt businesses expires September 30, 2026, dropping to 50% thereafter. Companies should accelerate negotiations with suppliers about taxable-status conversion.

Subcontract Act Reforms

The Japan Fair Trade Commission has tightened price pass-through guidelines, increasing scrutiny of abuses of superior bargaining position. Documenting contract terms is essential.

Attorney Yusuke Abe

FREE CONSULTATION

Corporate Law: your first 30 minutes are free

  • ・Handled by Yusuke Abe, admitted in Japan and New York
  • ・Online (Zoom etc.) or at our office in Otemachi, Tokyo
  • ・In English or Japanese

5. Criminal and Administrative Law

Cannabis Control Act — 18 Months In

The newly created cannabis use offense drove drug-related arrests to a record 6,000+ in 2025. Trends in suspended sentencing for first-time offenders are being closely watched.

Anti-Fraud and "Yami Baito" Countermeasures

Undercover identity operations and role-play investigations are now part of the police toolkit against organized fraud and recruited-criminal schemes.

Retrial System Reform (under deliberation)

Following the Hakamata case, the Diet is considering a Criminal Procedure Code amendment that would impose a one-year deadline on prosecutorial appeals of retrial orders.

6. Constitutional and Judicial Developments

Same-Sex Marriage Cases Referred to Grand Bench (March 25, 2026)

The Supreme Court's Third Petty Bench referred six same-sex marriage cases to the Grand Bench. A first-ever Japanese Supreme Court constitutional ruling on same-sex marriage is expected by early 2027.

Final Transition to "My Number" Health Card

Issuance of conventional health insurance cards stopped in December 2024, and grace-period expirations are now reaching medical providers in earnest.

Implementation Checklist for Businesses

  1. Review HR rules and policies (customer-harassment, parental leave, part-timer enrollment)
  2. Update contract templates (Freelance Protection, Subcontract Act)
  3. Audit electronic recordkeeping systems
  4. Run employee training (harassment, compliance, drug awareness)
  5. Revisit invoice-system supplier strategy before the October 2026 credit reduction

Conclusion

April and May 2026 mark the most concentrated wave of statutory enforcement Japan has seen in a decade. Companies should audit their HR, legal, and accounting functions concurrently. For specific provisions, see our dedicated articles on each topic.

For tailored advice, please consult with a qualified attorney.

Free Tools for This Area

Share this article
This article provides general legal information and does not constitute legal advice. For specific legal issues, please consult with a qualified attorney.

More Legal News

Related Articles

Can You Commercially Use Generative AI Output in Japan? Copyright Article 30-4 and Output-Stage Risk

A guide for businesses on whether generative AI output can be used commercially in Japan: Article 30-4 of the Copyright Act and its proviso, the similarity and reliance test at the output stage, how training data affects reliance, when AI-generated material is protected by copyright, injunctions, damages and criminal penalties, and steps you can take now.

Entering Japan as a Foreign Company: Representative Office, Branch or Subsidiary, and the Governing Law of Your Contracts

How a foreign company can enter Japan through a representative office, a branch or a subsidiary, explained against the Companies Act: the ban on continuous transactions before registration, the representative in Japan, KK versus GK, governing law and jurisdiction clauses, Foreign Exchange Act filings, and the October 2025 changes to the Business Manager status of residence.

Acquiring or Investing in a Japanese Company: Prior Notification and Post-Investment Reports under Japan's Foreign Exchange Act

How Japan's Foreign Exchange and Foreign Trade Act applies when a foreign company buys shares in, or invests in, a Japanese company: who counts as a foreign investor, the one-share rule for unlisted companies and the 1% threshold for listed ones, designated sectors and prior notification, the 30-day waiting period and its extension, the prior-notification exemption and core sectors, 45-day post-investment reports, and the reform taking effect on 4 January 2027.

Buying a Japanese Company: Share Transfer vs Business Transfer, and What Due Diligence Covers

For companies, including overseas buyers, acquiring a small or mid-sized Japanese company: how a share transfer differs from a business transfer under the Companies Act, the Civil Code and the Antimonopoly Act, and MHLW guidelines. Approval of transfers of restricted shares (Companies Act, Articles 136-139 and 145), delivery of share certificates (Article 128), the special shareholder resolution for a business transfer (Articles 467 and 309(2)(xi)) and dissenting shareholders' appraisal rights (Article 469), the seller's non-compete (Article 21), liability where the trade name is continued (Article 22), individual employee consent (Civil Code, Article 625(1)), JFTC prior notification and the usual scope of legal due diligence.

Japan APPI Data Breach Reporting for Foreign Companies: Extraterritorial Reach, Deadlines and Notifying Individuals

Foreign companies that supply goods or services to people in Japan can be bound by Japan's data breach reporting duty even without a Japanese office. This guide covers extraterritorial reach, the four reportable situations, the preliminary report (roughly 3–5 days) and final report (30 days, or 60 days for wrongful-purpose incidents), notifying individuals, penalties and the amending act promulgated in July 2026.

Setting Up a Company in Japan: Kabushiki Kaisha (KK) vs Godo Kaisha (GK) — Differences, Costs and Procedure

A comparison of Japan's two main company forms, the kabushiki kaisha (KK) and the godo kaisha (GK): formation costs, governance, profit distribution, transfer of interests and public notice of accounts, with the steps to incorporate and points to consider when choosing.

Related Q&A

Related reading

Corporate Law

Can You Commercially Use Generative AI Output in Japan? Copyright Article 30-4 and Output-Stage Risk

A guide for businesses on whether generative AI output can be used commercially in Japan: Article 30-4 of the Copyright Act and its proviso, the similarity and reliance test at the output stage, how training data affects reliance, when AI-generated material is protected by copyright, injunctions, damages and criminal penalties, and steps you can take now.

Corporate Law

Entering Japan as a Foreign Company: Representative Office, Branch or Subsidiary, and the Governing Law of Your Contracts

How a foreign company can enter Japan through a representative office, a branch or a subsidiary, explained against the Companies Act: the ban on continuous transactions before registration, the representative in Japan, KK versus GK, governing law and jurisdiction clauses, Foreign Exchange Act filings, and the October 2025 changes to the Business Manager status of residence.

Corporate Law

Acquiring or Investing in a Japanese Company: Prior Notification and Post-Investment Reports under Japan's Foreign Exchange Act

How Japan's Foreign Exchange and Foreign Trade Act applies when a foreign company buys shares in, or invests in, a Japanese company: who counts as a foreign investor, the one-share rule for unlisted companies and the 1% threshold for listed ones, designated sectors and prior notification, the 30-day waiting period and its extension, the prior-notification exemption and core sectors, 45-day post-investment reports, and the reform taking effect on 4 January 2027.

Corporate Law

Buying a Japanese Company: Share Transfer vs Business Transfer, and What Due Diligence Covers

For companies, including overseas buyers, acquiring a small or mid-sized Japanese company: how a share transfer differs from a business transfer under the Companies Act, the Civil Code and the Antimonopoly Act, and MHLW guidelines. Approval of transfers of restricted shares (Companies Act, Articles 136-139 and 145), delivery of share certificates (Article 128), the special shareholder resolution for a business transfer (Articles 467 and 309(2)(xi)) and dissenting shareholders' appraisal rights (Article 469), the seller's non-compete (Article 21), liability where the trade name is continued (Article 22), individual employee consent (Civil Code, Article 625(1)), JFTC prior notification and the usual scope of legal due diligence.

Corporate Law

Japan APPI Data Breach Reporting for Foreign Companies: Extraterritorial Reach, Deadlines and Notifying Individuals

Foreign companies that supply goods or services to people in Japan can be bound by Japan's data breach reporting duty even without a Japanese office. This guide covers extraterritorial reach, the four reportable situations, the preliminary report (roughly 3–5 days) and final report (30 days, or 60 days for wrongful-purpose incidents), notifying individuals, penalties and the amending act promulgated in July 2026.

Corporate Law

Setting Up a Company in Japan: Kabushiki Kaisha (KK) vs Godo Kaisha (GK) — Differences, Costs and Procedure

A comparison of Japan's two main company forms, the kabushiki kaisha (KK) and the godo kaisha (GK): formation costs, governance, profit distribution, transfer of interests and public notice of accounts, with the steps to incorporate and points to consider when choosing.

Attorney Yusuke Abe

FREE 30-MIN CONSULTATION

Talk to a lawyer about the issues in this article

Yusuke Abe, admitted in Japan and New York, will handle your matter — in Japanese or English, online or in person.

Book a free consultation