nikala has already given some fine contributions for Sonoko Kawai（河合その子）. Allow me to give one as well. Back in my university days, I was able to borrow a mix tape of aidoru songs from my friend for which, unfortunately, the singers' names and titles weren't listed. A few of the songs did stand out, including one which had this drumming that sounded like a heart processing a bit too much sugar, and a French accordion-like synth making a breezy entrance.
Finally, I found out a few sleeps ago that it was Kawai's 3rd single, "Aoi Station" (Blue Station), written by Yasushi Akimoto（秋元康） and composed by Tsugutoshi Goto（後藤次利）, and released in March 1986. I think it was that accordion which hooked me into the rest of the song....could imagine Sonoko traipsing down the Champs-Elysees to it.
"Aoi Station" was created as the campaign song for Hi-Soft, a caramel manufactured by confectioner Morinaga. Originally, it had been first given the title of "Omoide Kigaete"（思い出着替えて...Change Your Memories）. However, the director behind the recording wanted a French-sounding title, so a switch was made to "Kaze no Chelsea"（風のチェルシー...Chelsea of the Wind）. But, there were a couple of problems with that solution: 1) "Chelsea" isn't exactly a French word, and 2) Chelsea was a name of a product of one of Morinaga's corporate rivals, Meiji....rather awkward for a commercial. So, the folks went with "Aoi Station" with the katakana going with the French pronunciation of that second word in the title. What people have to do to get an aidoru song produced....boggles the mind.
In any case, "Aoi Station" was a huge hit for Kawai, reaching the top spot on Oricon, and ending up as the 10th-ranked single for 1986. Now that I've got one aidoru mystery solved, it's time to track down some of the others from that mystery tape.