Hikki has the best voice in my opinion. Her vocal range is amazing. And she doesn't need to change her voice, because she had a strong voice from her debut!
I think Namie has a good voice too, but sometimes I can't really tell because she uses a lot of harmony layers in her songs.
Also OLIVIA has an amazing voice!
And though Ayu is not the best, I love her voice. (I'm a bit confused as to why people are on an Ayu forum, if they don't like her voice
hahaha)
I also think Riyu Kosaka has an amazing vocal range.
