One of the biggest hits in 70s in Japan and the most famous Japanese female duo of all time.
Then, the most famous music choleography in Japan which all of Japanese ladies copied their dance.
The song's title means Unidentified Flying Object and there was a huge nationwide boom in 70s regarding UFO and cryptids(i.e; Yeti and Nessie) which was not so much attracted the people in Europe. May be more Japanese know Nessie than people in UK.
In my general view, more Japanese trust that ghosts, UFO, and Yeti exist than European do.
Although there was a cold war between US and USSR in 70s and Japan is relatively close to USSR, Japanese had much attention on UFO than Soviet nuclear missile.
However, Japanese are much keen on North Korean missile than UFO these days.