Dark Patterns in Japan: Prevalence & Regulatory Responses

Dark patterns—user interface (UI) designs that exploit users’ cognitive biases to steer them toward unintended and disadvantageous choices—are increasingly being recognized as a critical issue in Japan. These manipulative practices are not always born from malicious intent; they often emerge from routine conversion rate optimization and A/B testing, making them a structural problem.

Prevalence in Japan

The widespread use of dark patterns in Japan was starkly highlighted by a survey of 102 major websites, published by the Consumer Affairs Agency (CAA) in March 2025 as a research paper by its affiliated researchers. The most pervasive tactic identified was pre-selection (e.g., pre-checked boxes for paid options or newsletters), found on over 70% of sites. In some sectors, including major shopping, food, and cosmetics sites, this practice was observed on 100% of the platforms surveyed. The second most common was false hierarchy—visually emphasizing the provider’s preferred option (like a premium plan) while obscuring alternatives—which was present on approximately 70% of sites.

Other highly problematic types include:

– obstruction:

This involves making user actions, particularly cancellations, deliberately difficult. While registration is simple, terminating a service may require complex procedures, such as navigating multiple confusing web pages or convoluted automated phone systems. Japanese authorities have taken administrative action against cosmetics e-commerce operators for such practices.

– sneaking:

This category covers deceptive practices like hidden subscriptions (e.g., free trials that auto-renew into paid plans without clear disclosure) and drip pricing (revealing mandatory fees like shipping or service charges only at the final checkout stage).

Regulatory Landscape in Japan

Japan does not currently have a single, comprehensive law specifically targeting dark patterns. Instead, regulators are applying existing legal frameworks to address these practices:

– Act on Specified Commercial Transactions:

Amendments in recent years have strengthened measures against deceptive subscription models. The Act mandates clear disclosure of subscription terms and cancellation methods on the final confirmation screen. Violations, including obstructive cancellation processes, have been a primary basis for administrative actions.

– Act against Unjustifiable Premiums and Misleading Representations:

This law combats misleading representations of price or quality. Tactics like drip pricing or fabricated social proof (e.g., fake reviews) can fall under its purview. Furthermore, stealth marketing (undisclosed advertising), which is conceptually related to dark patterns, became a regulated offense under this Act in October 2023.

– Act on the Protection of Personal Information:

Consent for data processing obtained via a misleading or manipulative UI may be deemed invalid.

Conclusion and Outlook

While dark patterns might boost short-term metrics like conversion rates, they carry substantial long-term risks, including regulatory penalties, customer complaints, and irreversible damage to brand trust. Moreover, these practices raise significant competition policy concerns. They risk distorting fair competition—based on price and quality—and creating a market where “bad practices drive out good”. Certain tactics may even constitute “deceptive customer inducement” under the Antimonopoly Act.

The research paper concludes by highlighting key policy perspectives and future challenges. It recommends that regulatory frameworks assess the combined effects of dark patterns rather than just isolated tactics, calls for the reorganization of classifications to fit the domestic context, and emphasizes the necessity of further empirical experiments to measure consumer impact and clearly distinguish manipulative patterns from legitimate marketing techniques.