Kim Jong Il’s eldest son, Kim Jong Nam, was expected to succeed his father’s rule until he got caught trying to sneak into Japan to go to Disneyland. So that Disneyland trip prevented him from being supreme ruler of North Korea.

Kim Jong-nam

In May 2001, Kim was arrested in Japan on arrival at Narita International Airport, accompanied by two women and a four-year-old boy identified as his son. He was travelling on a forged Dominican Republic passport using a Chinese alias, Pang Xiong. After being detained he was deported to China, where he said he was travelling to Japan to visit Tokyo Disneyland. The incident caused his father to cancel a planned visit to China due to the embarrassment it caused him.

2001–2005: Loss of favour

Until the Tokyo incident, Kim was expected to become leader of the country after his father. In February 2003, the Korean People’s Army began a propaganda campaign under the slogan “The Respected Mother is the Most Faithful and Loyal Subject … Continue Reading

Source: https://en.wikipedia.org/wiki/Kim_Jong-nam#2001:_Tokyo_Disneyland_incident