Found out about Chie Sawa（沢チエ）through one of the "Light Mellow" discs but it was for another song. However, I did find this even better tune performed by her on YouTube.
There's very little written about the Kobe-born Sawa that I could find anywhere since she also doesn't have any representation on J-Wiki. But I could discover on this slow-uploading site that her bass-playing uncle introduced her to the music path, and at the age of 20, while she was performing in hotel lounges and nightclubs in Osaka, she was scouted by the president of the Ozawa Music Office, an entertainment agency that is currently based in Tokyo. Then according to the "Showa Pop Encyclopedia", she made her debut in August 1971 with the Japanese-language cover of Michel Fugain's "Balade en Bugatti" under the title of "Koi no Bugatti"（恋のブガッティ...Bugatti of Love）.
Her first LP was released in July 1974, "Ni-juu-san Sai" (23 Years Old). I gotta say that the title track is pretty kakkoii with that languid piano and guitar intro that reminds me a fair bit of Al Stewart, and Sawa's vocals have that resonant clarity reminiscent of Misato Watanabe（渡辺美里）. "Ni-juu-san Sai" is cool as menthol all throughout with its urban beat and the addition of a rock guitar in the instrumental bridge. As was the case with "Koi no Bugatti", lyricist Kazumi Yasumi（安井かずみ）provided the lyrics while music and arrangement were handled by Makoto Yano（矢野誠）.
According to the discography that has been listed on "Showa Pop Encyclopedia", beyond the album "Ni-juu-san Sai", Sawa only released one more record, a fourth single but under her real name of Chie Kunigita（国木田チエ）in 1976. Another Fugain song, "Une Belle Histoire" from 1972, was given its own Japanese cover by vocal group Circus under the title of "Mr. Summertime".