Gameboy Kids (2000)

Yip Sin-man (Andy Lau) is a grown man with a mentality of a five-year-old who is taken by two members of the Ministry of Foreign Affairs from China to India to study. Despite his mental condition, Yip is a quick learner. Wong Kau-tau, revealed to be three-foot tall man, is also at the Indian airport before being arrested by the airport police for breaking a telephone. In the process, Wong drops his passport and an Indian kid picks it up. Mistaking Wong for Yip, the kid hands the passport to Yip and he leaves for Hong Kong with the two ministers left behind.