Tokyo court rules an AI-cloned voice is legally protected — Japan’s first vocal-identity verdict

The Tokyo District Court ruled on Wednesday that a human voice is protected under Japan’s publicity rights — the first time a Japanese court has said the unauthorized AI cloning of someone’s voice can be a legal wrong. The verdict lands at the end of a closely watched case: Kenjiro Tsuda, the 55-year-old anime voice actor best known as Kento Nanami in Jujutsu Kaisen, sued TikTok last November over 188 videos he says featured an AI-generated clone of his “deep” and “lustrous” baritone.

The case#

Tsuda claimed the videos, posted from an anonymous TikTok account between July 2024 and September 2025, were narrated by a voice that could only be his — generated, his legal team concluded after voice-data analysis, by generative AI. The account combined images with AI-spoken content about urban legends, the occult, and conspiracy theories; its profile picture resembled Tsuda’s Jujutsu Kaisen character.

It was a business, not a fan edit. At its peak the account had more than 200,000 subscribers, and Tsuda’s complaint estimated it was earning between ¥500,000 and ¥750,000 a month, according to Kyodo. TikTok argued the voice was merely “generic” and that any resemblance was subjective.

The ruling#

Presiding Judge Aya Takahashi held that “the unauthorised use of a performer’s voice can be considered an infringement on publicity rights,” describing a voice as “as symbolic of one’s personality as portraits are.” But the protection is not absolute: it applies, the court said, when “the purpose of using that voice is exclusively to take advantage of its commercial appeal.” In other words, the test is not how good the clone sounds — it is whether the copier is trading on the performer’s identity.

Tsuda won the principle but not everything he asked for. The court dismissed his request to force removal of the videos, since the anonymous user had deleted them soon after the suit was filed. His lawyer Takashi Hirano conceded the verdict “ended up making both sides look victorious.” TikTok said it would “respect the court’s judgment while considering what steps to take after scrutinising [the ruling’s] details,” adding it would “continue to sincerely work on the balance between technology development and rights protection.”

Why it matters#

The lawsuit is believed to be Japan’s first seeking to defend vocal identity against AI-generated copies — and it lands in an industry with everything at stake. In Japan, voice actors are often stars on the level of their anime characters, and AI mimicry is seen as an existential threat to livelihoods built on trained voices. “An actor’s voice is the result of years of rigorous training and apprenticeship,” Yuko Sasaki, executive director of the Japan Actors Union, said ahead of the ruling. In 2024, Japanese actors launched the “No More” campaign opposing unauthorized use of their faces and voices in AI-generated content.

The court was not writing on a blank slate, either: in August, a Justice Ministry expert panel issued guidance that voices, like images, should be protected under publicity rights. Wednesday’s verdict gives that position its first judicial teeth — and a concrete legal standard that platforms and content creators in Japan will now have to navigate before cloning a distinctive voice for views.

What to watch#

The “commercial appeal” test is doing the real work here. Pure fan imitation without a commercial purpose may fall outside the ruling’s reach — but monetized AI narration trading on a known performer’s vocal identity now has a clear legal target painted on it in Japan. Expect this verdict to be cited the next time a platform is asked why it won’t pull a cloned voice, and watch for Japanese voice agencies to start demanding takedowns with a court citation attached.