Yusuke Wajima applied Hobsbawm's method to the Japanese "traditional" song "Enka" in his book "The Invention of a Legend of Japanese Sprit".
In this book he said that “Enka” (in the modern meaning) which is believed to be "traditional" and "indigenous" was invented in the late 1960s and have an only 40 years history. Its heyday had lasted just a dozen years from 1970s to the first half of 1980s.
Hibari Misora who though to be a typical "Enka" singer nowadays had sung various songs which were not categolized in "Enka" in the first half of her carrier before the notion of the "Enka" was invented. But people are forgetting that she sung a great variety of songs as she is getting thought to be an "Enka" singer. Hibari Misora singing the song "Yawara" is just an "Enka" singer, but she singing the song "Tokyo Kid" seems to be a western style singer.
In the late 1960s when the notion of the "Enka" was invested the second movement against the Japan-U.S. Security Treaty spread in Japan. Going against Japan Communist Party which was willing to built a "western", "modern", "healthy" and "cheerful" culture, the radical left movement made a "Japanese", "indigenous", "decadent" and "dirty" counterculture. For example there were underground theaters "アングラ演劇", BUTOH "暗黒舞踏", Ken Takakura's Japanese mobster's (Yakuza’s) movies "任侠映画" and small room folk songs "四畳半フォーク".
"Enka" which is thought to be "Japanese", "indigenous", "decadent" and "dirty" appeared at the same time when these elements of the counterculture appeared, and this fact means that "Enka" was related to the counterculture movement at that time. Keiko Huji's (who is Hikaru Utada's mother) song "Keiko's a Dream Opens in Midnight" is really a "Japanese", "indigenous", "decadent" and "dirty" "Enka", whose movie on YouTube was the radical left movement with a good reason.
The values, which "Keiko's a Dream Opens in Midnight" was based on, was the same as Carmen Maki's "Pretending a Child Whose Mother's Gone". The fact that Carmen Maki belonged to the underground theater "Tenjo Sajiki" means that the counterculture movement at that time and "Enka" had a relationship. "Japaneseness" and "traditionalism" of Ken Takakura's Yakuza movies were "new" in their historical context, and in the same way "Keiko's a Dream Opens in Midnight" was "new" at that time.
Kensuke Suzuki, a sociologist pointed affection for unhappiness in the songs of Miriya Kato, Kana Nishino and all that who are so called "R&B divas" and called such songs "Gal's Enka". (pp347-348)
It might be true that they, especially Miriya Kato with her looks, are orthodox successors of Keiko Fuji.