The quality of this Pikachu is so good, it's scary.
I can't tell whether a person or an AI drew it.
--An animator working for a Tokyo-based production company
"This Pikachu" was drawn by generative AI. From One Piece to Spy x Family, AI is producing countless images that mimic existing anime.
Generative AI is rapidly evolving, using innovative methods to produce text, images, video and audio. Although new copyright rules are on the way, the illicit use of AI is undermining anime, the gasoline in Japan's soft power engine. A Nikkei investigation reveals how AI anime is flooding the internet.
June 6, 2024
Large numbers of generated anime images are published on generative AI image sharing websites that attract users from around the world. Anyone can generate images to their liking and post them. A search on multiple sites for the names of the main characters of 13 globally popular anime titles turned up over 90,000 images.
With the help of experts, Nikkei found about 2,500 images that had multiple similar features to the original anime images.
Copyright-infringing images include not only those from uber popular anime franchises but also from recent works.
Pikachu -- over 1,200 images
Original
AI Image
With a cumulative intellectual property (IP) revenue of $92.1 billion through 2019, Pokemon is the global leader. Nikkei found over 1,200 images similar to Pikachu, the main character of the series.
Nikkei compared the images of Pikachu with that on the official website to see if there were similar features. Pikachu is a fantasy character with many unique characteristics. Some of the images could potentially damage the brand: the face was the same but the body was that of a different creature, or the image was arranged to hold a gun, for example.
Mario -- indistinguishable from the real thing
Original
AI Image
There were about 470 images of Mario, the main character from Nintendo's "Super Mario" game and anime franchise. One image depicts him in his characteristic jumping pose. Another shows him alongside a Donald Trump-like figure. Some were so accurate that they might as well have been originals.
Luffy -- merged with other works
Original
AI Image
Luffy, the main character from One Piece, can be found depicted as American superheroes like Batman and Spider-man. The face is Luffy's, just not the body and attire.
Suspected infringement of recent anime
AI Image
Anya Forger
Tanjiro Kamado
Yuji Itadori
Denji
Kitty
Conan Edogawa
Images from civitai, pixai.art, and seaart.ai
Series from the past few years such as Demon Slayer and Spy x Family have not been overlooked by generative AI.
The illustrations vary in style, from anime to live-action. Users also create their favorite backgrounds -- cityscapes, bedrooms, naturescapes -- and alter the characters' facial expressions and poses. Some of the images are so similar to the original works as to be indistinguishable from the real thing, at least at first glance.
Many generated images of female characters are popping up as it appears copyright infringement spreads beyond the realm of main characters.
Generate, upload, share
Image from seaart.ai
Generative AI "learns" by taking in huge amounts of data, then uses its digital education to generate the desired content. Generative AI image sharing sites allow users to enter prompts to generate and publish images. While users can create images for use on their personal computers without problem, posting this content to a sharing site might constitute copyright infringement if it too closely resembles existing copyrighted works.
Character names in 90% of prompts
An analysis of about 2,500 prompts found that roughly 90% contained the name of a character. In some cases, the names of anime works were included, suggesting that users intentionally generated similar images.
Examples of prompts
(partial excerpt)
Images from civitai, seaart.ai
"There is the possibility of AI unexpectedly generating images that infringe on copyrights," said Kotaro Tanabe, an attorney at Mimura Komatsu Law Firm regarding Nikkei's investigation. "If a character's name is included in the prompt, it is more likely to be recognized as infringement."
In Japan, determining copyright infringement depends on "similarity," whether the characteristic expressions are similar. There is also a "reliance" standard, whether an existing work is referenced. Although there have been no court cases in Japan relating to generative AI images infringing on copyright, the hurdles for dealing with them are higher since many images can be generated almost instantly.
In February, China's Guangzhou Internet Court found that an AI-generated image that closely resembles Ultraman constituted copyright infringement. This highlights the fact that Japanese content is being targeted.
Behind the flood of AI anime images is the reality that these works are being machine-learned without permission from the copyright holders. According to "Anime Industry Report 2023” by The Association of Japanese Animations, the market for globally distributed anime is worth almost 3 trillion yen ($19.30 billion). Rapid technological advances in generative AI pose a threat to the anime industry.
'New piracy' in the age of AI
In this investigation, Nikkei analyzed images posted to three image-sharing websites. They were civitai, which according to a study by the University of Electro-Communications had about 23.2 million monthly accesses as of April, pixai.art, which has over 8 million users, and seaart.ai.
Over 1,600 images similar to copyrighted originals were found on civitai. "It's possible that content from pirate sites is being used to train generative AI," said Professor Eriko Watanabe of the University of Electro-Communications, who has long conducted research on pirated content on the internet. "Unlike piracy until now [in which original works are illegally copied], it could become a 'generated AI pirate version' that can be arranged as the user likes."
"Many of the sites that generate and share these images do not publish the dataset of illustrations from which they are trained," she added. "A large amount of copyrighted material may be used for training without permission, and it is truly a 'black box' situation."
Over 200 images generated per month and distributed from overseas servers
2022 became the “first year of image-generation AI” as services such as StableDiffusion and Midjourney appeared on the scene. Since then, AI services that can easily generate images -- images that ignore copyright -- have been generated one after another. In 2024, over 200 a month were confirmed. According to the University of Electro-Communications, they all reside on servers outside Japan.
Civitai replied to Nikkei, "Civitai respects and values the intellectual property (IP) of artists. [...] We promptly investigate and take necessary action, including removing infringing content and terminating accounts of repeat infringers in accordance with U.S. law." Requests for pixai.art and seaart.ai to comment went unanswered.
A world heading toward regulation
Generative AI and copyright in each jurisdiction
EU
Adopts world's first regulation in May (demands transparency in AI products).
U.S.
The court system takes up disputes when they arise and determines legality.
Japan
There are cases of rights infringement when copyrighted works are used for training without permission.
Rapidly evolving generative AI faces further regulation. In May, the Council of the European Union gave final approval to the world's first comprehensive regulation on the development and use of AI. The rules require transparency guarantees, such as requiring generative AI service providers to clearly state that products are made by AI.
In the U.S., the "fair use" doctrine allows for copyrighted works to be used if certain conditions are met. If disputes about a new service arise, courts take them up and decide on what is and what is not legal. In recent years, AI development companies have been sued.
Japan's Agency for Cultural Affairs in March compiled a report on the possibility of copyright infringement in AI's unauthorized use of text, images and other content. More than 20,000 public comments were received from industry groups and individuals, raising concerns about unauthorized training.
The dawn of generative video AI
From images to video… In 2024, OpenAI and Google announced a series of high-performance AI video generators. The high-quality videos are an innovation that fundamentally changes the way content is presented but also raise the specter of further copyright infringement concerns.
Video made by generative video AI Sora; from Open AI website
"When generative AI is democratized, everyone will be able to create anime," said Professor Daiya Hashimoto of Digital Hollywood University, a specialist on generative AI trends. "Tens of millions of new types of creators will emerge." To protect copyrighted Japanese anime, “it would be a good idea to develop a technology that uses AI to detect images that infringe on copyright,” he added.
Japanese anime is entering a new phase in how it will evolve in the generative AI era.
Methodology for investigation of generative AI images
Multiple reporters classified images after receiving guidance on how to determine copyright infringement from attorney Ryoichi Mimura of the Mimura Komatsu Law Firm. Mimura has handled many intellectual property cases as a judge.
Original images were selected from the official websites of the relevant content companies and other sources, and images with multiple similar characteristics were extrapolated. Even if the faces of the characters differed slightly, they were included in the analysis if the overall image was similar. Altered images were also considered as the same character.
Anime for the investigation were selected from the top 10 in cumulative IP revenue through 2019 and the top 10 in terms of the number of viewers in 2022.
Anime and characters investigated
Cumulative IP revenue through 2019
| 1 | Pokemon (Pikachu) |
|---|---|
| 2 | Hello Kitty (Kitty) |
| 6 | Anpanman (Anpanman) |
| 8 | Super Mario (Mario) |
Source: Briefing material of Japan Business Federation
Number of domestic video streaming service viewers (2022)
| 1 | Spy x Family (Anya Forger) |
|---|---|
| 2 | Demon Slayer (Tanjiro Kamado) |
| 3 | One Piece (Monkey D. Luffy) |
| 4 | Detective Conan (Conan Edogawa) |
| 5 | Attack on Titan (Eren Yeager) |
| 6 | Kingdom (Shin) |
| 7 | Chainsaw Man (Denji) |
| 8 | Jujutsu Kaisen (Yuji Itadori) |
| 10 | Gundam (Amuro Ray) |
Source: Anime Industry Report 2023
NIKKEI Film
Japanese anime vs. generative AI
Nikkei Asia
Infographics
- Reporting Team
- Hirofumi Yamamoto, Akinobu Iwasawa, Toru Yamada, Sotaro Sakai, Ryohei Senzaki, Marina Nakagawa, Hiroyuki Miyashita, Kazuhiro Kida and Ken Kobayashi