True Left

Yamaguchi was most certainly not specifically a singer. Her Akai series of dramas dominated the 70s:



The heroine archetype that she established would go on to be imitated for many years after her early retirement*. (Only Minamino (to her credit) ignored it and thus belatedly brought in the 80s archetype.) The way I would describe it is that it took Kudo and Minamino combined to dethrone Yamaguchi, the former displacing her musically and the latter dramatically. This in itself is a tribute to Yamaguchi's outsized impact in pop culture.

(* This was also Yamaguchi's wisest move, as it meant the world would never have to watch her decline.)