Honestly to me the promotion/marketing of Kpop idols has always been similar to Jpop idols, especially in the past. It's just that eventually Kpop actively tried to reach out to international audience, which differentiated itself from Jpop.
Also idol boygroups in Japan back then was like 100% Johnny's lol, the grip they had on Japanese showbiz was crazy, none of the big4 company in Korea has the same amount of influence that J&A had/has. They've lost their footing a bit imo with SMAP disbanding, Arashi going on hiatus and the rise of survival show boy groups, but they're still an unshaken force in Jbiz.
