Enka is a genre of music unique to Japan. It's been influenced by all kinds of things, from traditional instruments and melodies to modern pop.

Enka appeals mostly to older audiences in Japan - singers generally perform in kimono and have a particular style of singing that is evocative and listenable but rings of another age. Enka lyrics often deal with (surprise!) ephemera, sadness, and loss.

It could be considered analogous to Country Western music here - harkening back to an older time (kind of) but in reality influenced by new and ever-changing forces.

The only Enka artist I can think of right now is Fuyumi Sakamoto, but there are of course lots others, male and female. It is my suspicion that Kyu Sakamoto (of Sukiyaki fame) was very influential in shaping modern Enka.