For most audiences, when you talk about espionage thrillers the first thing that springs to mind might be handsome, well-built figures like Daniel Craig or Ethan Hunt.

But in the upcoming comedy Fat Buddies, the two protagonists that set out to prevent a daring crime are two over-weight agents who may just make your jaws drop.

Weighing around 150 kilograms each, the duo team up to try and crack a drug-trafficking ring operating in Japan.

The comedy starring actors Bao Bei'er and Wen Zhang as the titular duo will open across the Chinese mainland on Sept 30.

During filming, Bao and Wen had to spend a couple of hours every day having heavy makeup and especially designed suits to make them look fat to take on the role of their characters, Bao explained at a recent promotional event in Beijing.

He recalls Wen's suffered a severe face allergy barely a third of the way through shooting.

"I really appreciated Wen's professional spirit. He insisted on wearing makeup and finishing all the scenes," says Bao.

The cast of the film also includes Xun Juncong, Ke Lala, Zeng Yijun, Zhang Menglu, Guo Jingfei, and Japanese actor Yasuaki Kurata.