"Shinju no Pierce" (Pearl Earring), although it never came out as an official single in Yuming's massive discography, has become one of her well-known songs through concerts and the rash of BEST compilations that have been coming out over the past several years. Originally, it was a track on her 13th album, "Pearl Pierce" (Pearl Earring), and the singer-songwriter based it on the contents of a fan letter. Her modus operandi when it comes to how she creates her works has been to keep her eyes and ears open for pop cultural trends, especially as they affect women, so I would say that this song is a pretty representative Yuming tune.
Also, listening to her songs, either in her Yumi Arai（荒井由実） or Yumi Matsutoya（松任谷由実） era, is to get a feel for how she liked to arrange a song at the time. "Pearl Pierce" was released in June 1982, and "Shinju no Pierce" has a mix of straight-ahead pop with some old disco-funk. It's quite a-ways from her mid-70s New Music days. The intro especially with the guitar and the horns reminds me a bit of a song from way back, Love Unlimited Orchestra's "Love's Theme".
As I said, Yuming based the lyrics on a female fan's actual experiences of losing that guy to another woman. I'm not quite sure whether the song's description was quite as dramatic as what that poor fan had gone through, but the lyrics talk about a supposedly final tryst before the jerk takes off with his new conquest, and how the soon-to-be dumped lass throws that pearl earring under the bed. Although the melody is pretty chipper throughout the song, the strings get a little ominous near the end.
And for those who want to re-live those disco ball days, here is the Love Unlimited Orchestra.