^yeah right, coz that's brand new in her standards LMAO...

Kana is actually one of the few JAPANESE artist who actually tries different things with each release. Some song sound alike probably because she likes the genre herself. Of course it'll never be totally new, but GO FOR IT!! for example, was quite challenging for her as she never actually released a song like this as a single before. You may like it, you may not, but really, what's the big deal? it's not like you were planning on buying her music, am I right? I didn't like it, I didn't buy it, it's as simple as that. But I'll give it to her that she at least tried something different, and not another up tempo ballad about friendship or her past lover.
It was not my intention to sound rude or anything, I'm just plain sick of people complaining about an artist (not necessary Kana) not renewing herself/himself, when it's what she/he's been trying to do.. Of course there will be times when songs sound alike, she has a fanbase to maintain afterall, and she has to appeal to them too