There are at least 1,000 websites illegally offering free downloads of Japanese content, mostly its globally-renowned manga graphic novels, a group of domestic publishers claimed earlier this year.

But under a 300 million yen ($2 million) pilot scheme proposed by Tokyo's cultural agency, AI will scour the web for sites pirating manga books and anime cartoons, using an image and text detection system.

"Copyright-holders spend a significant amount of human resources trying to manually detect pirated content online," cultural agency official Keiko Momii told AFP on Tuesday.

But human moderators can "barely keep up" with constantly proliferating illegal content, the agency said in a written document.

The initiative features in the agency's supplementary budget request for this fiscal year ending in March.

It is inspired by a similar project in South Korea and if successful could also be applied to other illegally shared films and music.

Japan, the birthplace of comic and cartoon epics such as "Dragon Ball" and game franchises from "Super Mario" to "Final Fantasy", sees the creative industries as a driver for growth on par with steel and semiconductors.

In its revised "Cool Japan" strategy released in June, the government said it aims to boost exports of these cultural assets to 20 trillion yen ($130 billion) by 2033.

Around 70 percent of pirating sites offering Japanese content operate in foreign languages including English, Chinese and Vietnamese, Japanese publishers say.

In 2022, Japan's gaming, anime and manga sectors raked in 4.7 trillion yen ($30 billion) from abroad -- close to microchips exports at 5.7 trillion yen, government data shows.