ZHENGZHOU, China, Sept 22 — On a film set that resembles the medieval castle of a Chinese lord, Zhu Jian is busy disrupting the world's second-largest movie industry. The 69-year-old actor is playing the patriarch of a wealthy family celebrating his birthday with a lavish banquet. But unbeknownst to either of them, the servant in the scene is his biological granddaughter.

A second twist: Zhu is not filming for cinema screens. Grandma's Moon is a micro drama, composed of vertically shot, minute-long episodes featuring frequent plot turns designed to keep millions of viewers hooked to their cellphone screens — and paying for more. “They don't go to the cinema anymore,” said Zhu of his audience, which he described as largely composed of middle-aged workers and pensioners.

“It's so convenient to hold a mobile phone and watch something anytime you want.” China's US$5 billion a year micro drama industry is booming, according to Reuters' interviews with 10 people in the sector and four scholars and media analysts. The short-format videos are an increasingly potent competitor to China's film industry, some experts say, which is second in size only to Hollywood and dominated by state-owned China Film Group.

And the trend is already spreading to the United States, in a rare instance of Chinese cultural exports finding traction in the West. Three major China-backed micro-drama apps were downloaded 30 million times across both Apple's App Store and Google Play in the first qu.