Well I'm not too informed on the current details, but I have seen that Hikki's album has succeeded in pulling ahead of EXILE's best of.
http://ohnotheydidnt.livejournal.com/103565995.html
It's being talked about right now b/c this is the SECOND time that AVEX pulls this stunt, using one of their best record selling artists.
When I was still into JPop, I remember Utada Hikaru came out with her new album DISTANCE, and AVEX pulled a bitch move and used Ayumi Hamasaki (I dont think you need an explanation of who she is) to promote a BEST OF album. I remember because I bought both lol.
You would have had to have been in tokyo during 2001 to have seen the amount of promotion that AVEX went through to make sure Ayu's record sold.
BOTH CDs sold extremely well (we are talking hundreds of thousands on release), but Hikki's came out on top.
Ayumi was pissed off that she was being forced to make a best of album for AVEX greed (this led to bad blood between her and the company), and went on to apologize on her behalf.
Ayumi was already planning to release a greatest hits CD on her own, but AVEX shut her down, and had her do this instead.
Eventually I think it lead to Ayu being stressed out and worked to the point where she later became deaf in one ear.
So yeah lol