Thailand’s Nation Group news media conglomerate is investing in a forthcoming feature film “Nak Ruk Mak Makk Mak,” the company said. The film is a romantic comedy inspired by Thai ghost tale “Mae Nak Phra Khanong.”

Buoyed by a string of recent successes and a government initiative to bolster national soft power and the creative industries, Thai film is attracting new investors. Thai authorities plan to set up a promotional and funding agency spanning multiple forms of culture, including film, music, food and Muay Thai boxing.

At FilMart last week, Princess Ubolratana Rajakanya Sirivadhana Barnavadi hosted a lavish Thai Night promotional event. And the country’s Department of International Trade and Promotion, under the Ministry of Commerce, signed a memorandum of understanding with Hong Kong’s Trade Development Council.

“Nak Ruk Mak Makk Mak,” brings together four companies: Nation Group (Thailand) as investor, Black Dragon Entertainment as promoter and...