go read a book.
neither the japanese or the koreans originated the music or dance steps they are doing.
oh yes, koreans have been singing and dancing like that for years. tell me, what is the genesis of this particular form of singing and dancing? where did it develop in korea or japan? what kids in korea or japan started doing those dances and when?
oh, james brown, michael jackson, usher, etc. have somehow copped their dance moves and singing from taeyang, rain, and company.