The makers of China’s movie hit of the summer Nezha – which made box office history in August by becoming the country’s highest-grossing animated film of all time – are being sued for plagiarism.

A Beijing-based company claims Nezha is “extremely similar” to its onstage musical Memory. The case was accepted on Monday by the Beijing Intellectual Property Court and is being processed.

China Film Huateng claims Nezha’s director Yang Yu – known in the industry as “Jiaozi” – and Beijing Enlight Media plagiarized substantial elements of its musical and is demanding 50 million yuan (US$7.1 million) for economic loss, a further 1 million yuan to cover legal costs, as well as a public notice from the defendant.

A screen grab from Nezha, China’s summer smash animated film.

Nezha became China’s highest-grossing animated film on August 2, raking in more than 2 billion yuan (US$285.6 million) in its first week and breaking a record held by Zootopia (US$235.6 million) since 2016. It has also been picked as the country’s entry in the best international feature film category at the 2020 Oscars.

“The plaintiff claims Nezha is largely similar to Memory in character image design, plot and production elements, invading its rights,” a notice from the court said.

Beijing Enlight Media did not immediately respond to the South China Morning Post’s request for an interview.

The court action follows a series of notices released by Huateng on microblogging site Weibo in August and September, claiming Nezha had plagiarized its show, which has been running for three years in China, after four years of development.

“Since the animation film was released in theaters, many friends who had seen Memory say these two shows are extremely similar,” one notice said. “After investigating, we found the two works are highly alike in creation logic, plot development, the main characters’ personality setting, plot twists and many visual special effects.”

Posters for Nezha (left) and Memory. (Picture: Weibo)

Huateng has now declared it will not release any further details on similarities between the two works, “for the protection of evidence.”

Internet users have demanded to see more evidence of similarities and questioned how Nezha’s storyline could be similar to Memory, since the film was adapted from a well-known story in classical Chinese mythology.

Also in August, a designer announced on Weibo that his animated clip of the solar system was used in Memory without authorization. Huateng has said it is investigating and will take responsibility if there is any merit to the claim.