This article reviews the current legal framework for protecting a person’s voice in Japan, with particular focus on issues arising from AI-generated speech synthesis and voice imitation.

Potential Protection of Voices Under Current Laws

The discussion below does not contemplate the creation of a new statutory right in voices. Rather, it examines how existing laws and judicial doctrines may address unauthorized use of a person’s voice.

• Copyright Law

Potential protection under the Copyright Act includes copyright, authors’ moral rights, performers’ rights, and performers’ moral rights. However, a person’s vocal quality or tone itself is generally not regarded as a copyrightable work because it does not constitute a creative expression of thoughts or emotions. While scripts and narration texts may be protected by copyright, vocal characteristics themselves are not protected by copyright or authors’ moral rights.

Specific performances actually rendered by a voice actor, such as recorded performances, may be protected by performers’ rights and performers’ moral rights. However, where generative AI learns the characteristics of a voice and produces a new recording distinct from any existing performance, the output is generally difficult to characterize as a use of a particular prior performance. Accordingly, extending protection through performers’ rights or performers’ moral rights to the AI-generated voice is not straightforward.

As a result, under current law, it is generally difficult to assert copyright infringement solely on the basis that AI-generated voice imitates a person’s voice or vocal tone.

However, separate issues may arise at the training stage. If recordings of actual performances are used as training data, acts such as reproduction or making available for transmission may raise some legal issues. Such use may nevertheless be lawful under Article 30-4 of the Copyright Act if it is conducted solely for information analysis and not for enjoyment of the expressive content of the work or performance.

• Right of Publicity

In Japan, the right of publicity is generally understood as protecting the interest in the exclusive exploitation of the customer-attracting power possessed by a person’s name, likeness, and the like (“likeness, etc.”). Although there is no express statutory provision, the Supreme Court’s 2012 Pink Lady decision recognized a right to exclusively exploit such customer-attracting power and identified circumstances in which its unauthorized use may constitute a tort.

The Court held that unauthorized use of a person’s likeness, etc., may be unlawful where, for example, the likeness, etc., itself is marketed as a product, is affixed to goods to differentiate them, or is used in advertising, because such uses exploit the customer-attraction value associated with that person.

The decision concerned a person’s likeness rather than their voice and therefore did not directly address whether a voice falls within the scope of the right of publicity. Nevertheless, commentary on the decision has suggested that a voice may also constitute “likeness, etc”. Governmental discussions concerning AI and intellectual property have likewise highlighted the need to clarify the legal treatment of AI-generated voice use.

Even if voices are recognized as subjects of publicity-right protection, several issues remain.

First, because the right of publicity is generally regarded as deriving from personality rights, questions arise regarding its commercial exploitation, including licensing, assignment, and inheritance.

Second, protection depends on whether the voice possesses customer-attracting power. Individuals whose voices are not widely recognized by consumers may receive only limited protection.

Third, where an AI-generated voice is used for political statements, obscene content, or purely private purposes, it may be difficult to establish the required purpose of exploiting customer-attracting power. Such uses may nevertheless give rise to separate claims relating to personality rights, reputation, or privacy.

• Unfair Competition Prevention Act

Protection may also be sought under the Unfair Competition Prevention Act. Article 2(1)(i) prohibits use of a well-known indication of goods or business that causes confusion with another person’s goods or business, while Article 2(1)(ii) prohibits unauthorized use of a famous indication of goods or business.

To invoke these provisions in relation to a voice, it must be shown that the voice itself has become well known or famous as an indication identifying a particular person’s goods or business, and that the challenged conduct constitutes use of the voice as such an indication. Protection will therefore be difficult where the voice lacks sufficient public recognition. Likewise, in cases involving political expression or private use unrelated to commercial activities, it may be questionable whether the voice is being used as a business identifier.

Additional issues may arise where an AI-generated voice falsely suggests that a person endorses particular products or services, or where false statements disseminated through such a voice damage the business reputation of the individual or the individual’s agency.

Recent Litigation Concerning AI Voice Imitation

According to media reports, popular Japanese voice actor Kenjiro Tsuda has filed an action with the Tokyo District Court seeking removal of TikTok videos allegedly featuring AI-generated narrations imitating his voice.

Reports indicate that: Mr. Tsuda filed the lawsuit in November 2025; the disputed content consists of at least 188 videos posted between July 2024 and approximately September 2025 by an unidentified user; the plaintiff (Mr. Tsuda) alleges that the videos feature narrations imitating his distinctive vocal characteristics and attract viewers and therefore seeks their removal based on the Unfair Competition Prevention Act and the right of publicity; and the defendant argues that the narrations merely use a generic male voice and are neither sufficiently similar to Mr. Tsuda’s voice nor likely to cause confusion.

The case has attracted attention as a notable dispute concerning alleged unauthorized AI voice imitation. It may provide important guidance on whether and to what extent voices are protected under the right of publicity and the Unfair Competition Prevention Act, how similarity between voices should be assessed, how exploitation of customer-attracting power can be proven, and the extent to which platform operators may be required to remove allegedly infringing content.