Once I heard, I guess it was in "Ima no watashi" interview, that she didn't have that many concerts. And indeed, she didn't make a huge tour after every album (for example there was a few performances promoting Heart Station, but that was all - if I'm wrong, tell me). So I think she didn't pay big attention where she performed. BTW, I always thought that performing in Budokan is very important, I found out that a lot of concerts happened there... Anyways, Hikki is very well known in Japan, it desn't matter even if she hasn't sung in Tokyo Dome^^