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Corporate LawPublished: 2026-03-24/Updated: 2026-09-224 min readLawyer-Reviewed

Trade Secret Protection Under Japan's Unfair Competition Prevention Act

Key Takeaways

  • ✓Trade secrets require three elements: secrecy management, usefulness, and non-public knowledge
  • ✓Injunctions and damages are available against misappropriation
  • ✓Criminal penalties up to 10 years imprisonment or ¥20 million fine
  • ✓Establishing a daily secret management system is prerequisite for legal protection

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What Are Trade Secrets?

Trade secrets are technical or business information held by companies that are protected under Japan's Unfair Competition Prevention Act (UCPA). Typical examples include customer lists, manufacturing know-how, pricing information, and R&D data.

Three Requirements for Trade Secrets

To qualify as a "trade secret" under the UCPA, information must meet all three requirements (Article 2(6)).

Secrecy Management

Caution

The information must be managed as a secret. Merely intending it to be secret is insufficient; there must be objectively recognizable management measures.

Specific measures: - Marking documents as "Confidential" - Access restrictions on electronic data (passwords, permissions) - Non-disclosure agreements (NDAs) - Physical storage in locked locations - Clear notification to employees that information is confidential

Usefulness

The information must be useful for business activities. This includes both technical information and business information such as customer data and sales strategies.

Even failed experiment data may qualify if it helps avoid repeating mistakes.

Non-Public Knowledge

The information must not be publicly known. Information available in publications or on the internet does not meet this requirement.

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Types of Unfair Competition

The UCPA regulates the following acts regarding trade secrets as "unfair competition" (Article 2(1), items 4-10).

Wrongful Acquisition (Items 4-6)

  • Acquisition through theft, fraud, or coercion
  • Use or disclosure of wrongfully acquired information
  • Acquisition with knowledge (or gross negligence) of wrongful origin

Wrongful Use (Items 7-9)

  • Use or disclosure of legitimately obtained trade secrets in breach of duty of good faith
  • Former employees using trade secrets from their previous workplace
  • Using a former employer's trade secrets at a new company

Civil Remedies

Injunction (Article 3)

You can seek to stop unauthorized use or disclosure of trade secrets. Preventive injunctions are also available.

Damages (Article 4)

Compensation for losses caused by unfair competition. Presumption provisions (Article 5) reduce the burden of proof.

Credit Recovery (Article 14)

Courts can order measures to restore business reputation, such as corrective advertising.

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Criminal Penalties

Trade Secret Infringement (Article 21)

ActPenalty
Wrongful acquisition/use/disclosureUp to 10 years imprisonment or ¥20 million fine
Cross-border offenseUp to 10 years imprisonment or ¥30 million fine
Corporate fineUp to ¥500 million (domestic) / ¥1 billion (cross-border)

Attempted Offenses

Attempted trade secret infringement is also punishable (Article 21(6)).

Building a Secret Management System

A daily management system is essential for obtaining legal protection.

Information Classification

Clearly identify trade secrets to be protected and classify by importance level.

Access Control

  • Limit access to those with a "need to know"
  • Maintain and store access logs
  • Immediately deactivate departing employees' accounts

Contractual Protection

  • Confidentiality agreements with employees
  • NDAs with business partners
  • Confidentiality pledges upon departure
  • Non-compete obligations (within reasonable scope)

Training and Communication

  • Conduct regular training
  • Establish and communicate information management policies
  • Set up incident reporting systems

Responding to Data Theft by Departing Employees

Preventive Measures

  • Confirm confidentiality obligations during exit interviews
  • Verify whether company data has been taken
  • Collect work PCs and deactivate accounts

Post-Incident Response

  1. 1

    Preserve evidence

    Check access logs, emails and similar records, and preserve them as evidence.

  2. 2

    Send a warning

    Send a formal warning via registered mail.

  3. 3

    Apply for a preliminary injunction

    Apply for a preliminary injunction to stop unauthorized use or disclosure of the trade secrets (Article 3).

  4. 4

    Damages and criminal charges

    Pursue damages (Article 4) and/or criminal charges (Article 21).

Summary

Important

The key to legal protection of trade secrets is secrecy management. No matter how useful or non-public the information, it cannot be protected without proper management. Building a daily information management system and preparing for potential leaks is essential.

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

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