Photo/Illutration A pirated manga site that is believed to be the largest such operation. Part of the image is blurred intentionally. (Yasukazu Akada)

Four leading manga publishers are set to file a lawsuit against a U.S information technology company in early February, arguing it is breaching their copyrights by distributing data from pirate manga sites, according to sources.

The lawsuit to be heard by the Tokyo District Court targets Cloudflare Inc., a U.S. web infrastructure company that serves as a content delivery network.

Publishers Shueisha Inc., Kodansha Ltd., Shogakukan Inc. and Kadokawa Corp. will seek combined damages totaling about 400 million yen ($3.48 million), the sources said.

Some of the publishers were successful in shutting down Mangamura, one of Japan’s largest manga piracy websites, in 2018.

The publishers decided their best course to protect their copyrights was to pursue the responsibility of the provider of the content delivery network that pirate operators use as identifying such operators based overseas is extremely difficult.

The sources said one of the largest pirate magna sites was contracted with Cloudflare and that its server in Japan is used to deliver pirated manga.


The site receives around 300 million hits a month and delivers pirated versions of 4,000 works. They include extremely popular works, such as “One Piece” and “Attack on Titan.”

The publishers said Cloudflare’s content delivery network is essential for pirate operators to distribute a huge amount of data instantaneously when viewers access their sites.

Since April 2020, Kodansha, Shueisha, Shogakukan and Kadokawa had each notified Cloudflare in succession to stop delivering the pirated versions based on the U.S. copyright law, but to no avail. 

The companies estimated that they each suffered losses to the tune of billions of yen until late last year.

They will each seek about 100 million yen in partial damages as well as an end to the delivery of pirated and copied content.

A Cloudflare representative contacted by The Asahi Shimbun replied: “Cloudflare’s CDN and pass-through security services do not meaningfully contribute to infringement.”

After the closure of Mangamura, a similar site called Manga Bank appeared on the internet on 2019. But it, too, was shut down after the publishers filed an information disclosure request against the operators at a U.S. court.