AI tool that copied actor’s ‘lustrous’ voice violated his rights, says Tokyo court

A Japanese court has ruled that the human voice can be protected under publicity rights, marking a landmark legal victory for a well-known actor. The actor, Kenjiro Tsuda, best known for voicing Kento Nanami in the anime Jujutsu Kaisen, filed a lawsuit against a TikTok account that allegedly used AI technology to create videos mimicking his distinctive "lustrous" baritone voice.

The Tokyo district court held that voices hold the same protection as publicity rights, which grant individuals control over and profit from aspects of their identity. The court dismissed Tsuda's request for the removal of the videos, as they had been deleted shortly after the lawsuit was filed. According to presiding judge Aya Takahashi, unauthorized use of a performer's voice can be considered an infringement on publicity rights.

This legal battle is believed to be the first in Japan that seeks to defend an individual's vocal identity against AI-generated copies. Japan's voice actors, often achieving stardom through their anime appearances, are increasingly concerned that AI mimicry may threaten their livelihoods and the entire industry. Tsuda, 55, argued that the 188 TikTok videos uploaded between July 2024 and September last year were narrated by the same voice that could only be his.

In response, the platform argued that the videos contained a "generic male voice" and that any perceived similarities to Tsuda's voice were highly subjective. Despite this, the court upheld the ruling that the human voice is protected under publicity rights if the purpose of using the voice is solely for the commercial advantage of its owner.

The TikTok account, featuring images and AI-generated speech about urban legends, occult, and conspiracy theories, had over 200,000 subscribers and was reportedly earning its owner between ¥500,000 and ¥75,000 in monthly revenue. Tsuda's legal team claimed the account gained attention due to its cloned "attractive voice of a popular actor."

TikTok expressed respect for the court's judgment while considering what steps to take following the ruling, vowing to continue balancing technological development with rights protection. In 2024, Japanese actors launched a campaign called "No More" to oppose the unauthorized use of their faces and voices in AI-generated content.