
I'm intrigued by the contrast between the Billboard and Oricon charts. The numbers for Sandaime J Soul Brothers and Kiyoshi Hikawa are fairly consistent, which indicates that they are mainstream, while Morning Musume and UP10TION show the inflated numbers typical of idol groups, just to different degrees. It's a great example of why Oricon changed their rules, and it makes me wonder if the K-pop wave would have been as big as it was if Oricon had these rules all along.