Premise: "King of the Jungle" is a song written and recorded by English girl group Bananarama. It was released as a single in Japan only from their self-titled second album in 1984. The song is the second single from Bananarama to be a Japanese-only release (following "He's Got Tact" in 1982).
Hypothesis: In 1982 Bananarama released "he's got tact" in Japan, and only Japan, because of the lack of popularity in their home country of England.