[bulmasman]

I Can't recommend Akina Nakamori enough, she's SO good, better than Seiko even imo. There's also Noriko Sakai, Yoko Nagayama (though it's hard to find her older pop stuff). Also I'd like to recommend Miyuki Nakajima, she started back in the 70's, and has had a number 1 hit in every decade since, definitely worth checking out ^^.

There's also Onyanko Club, which i suppose is the precursor to the kind of big idol groups we have now, such as Morning Musume or AKB48.

Also, for something a little different... Mari Hamada and Show Ya... awesome 80's female jrock. Not to mention X Japan... greatest rock band of all time ^^