Good heavens! I should have remembered this song from that phrase uttered by Kyon-Kyon.
That doesn't mean I knew the title for the song. I actually found it again by accident a few nights ago on YouTube after having seeing it performed by Kyoko Koizumi（小泉今日子）way back in the 1980s via VHS. This would be "Nagisa no Haikara no Ningyo" (The Stylish Mermaid of the Beach), her 9th single from March 1984, and it's about as early 80s aidoru as it can get with this one. The arrangement of the chorus, the catchy summer beat and the coquettish vocals by Kyon-Kyon just spell it out for me.
Written by Chinfa Kan（康珍化）and composed by Koji Makaino（馬飼野康二）, "Nagisa no Haikara no Ningyo" relate the story of spotting and lusting after that beauty on the sands, and I'm pretty sure that a lot of the fans were casting the aidoru as that beauty.
The song was Koizumi's first No. 1 hit on Oricon and it would get the lass her very first ticket to the Kohaku Utagassen later on in the year. It sold somewhere around 330,000 records and by the end of 1984, it would become the 25th-ranking single.