I've seen a lot of singers out there in Japan(I dont just stick with KOTOKO now) but the majority of them dont get popular or even get a second glance when it's in America.

"Why do you say that?" you might be asking. here's MY theory about JRnB songs vs the Generic JPOP in America:

Yumi Shizukusa vs Hello!Project groups

Yumi Shizukusa is a wonderful artist who has that 'black girl' voice and specializes in RnB(i've heard a few generic JPOP songs from her but not that many). Then there's the H!P groups who specialize in singing (in Anime geek language: KAWAII!!!) cute generic songs that are usually used in animes.

The reason people dont listen to YumiShi is for some reason, they like the 'kawaii'ness of generic JPOP songs. The high voices, the cute lyrics and such. They dont look at the JRnB because either 1. RnB is already so popular or 2. The japanese singers who sing JRnB are trying to be black.

I like them all but I toward the JRnB because they dont get enough credit nor publicly because people are too busy listening to the generic JPOP.

I will admit, i LOVE Kotoko, I have the most song from her, I know most things about her, hell, I'm gonna make a tshirt with her on it but the reason she's popular is because she sings in the generic JPOP sound whether it be her high voice or low voice.

That's my mini rant about JRnB vs JPop generic. I'll probably add more.