No, I really don't think Kumi is going to take her place, she never could anyways. And I agree with v3lun420 about the whole Kumi thing too. My thoughts exactly

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But anyways, I hope Ayu will be alright, she should really take a break. And I'd give my left ear to Ayu in a heartbeat xD.
And one more thing...when Ayu leaves the music scene(Not saying I'd be happy if she did, honestly), I would really want Utada to take her place. She's practically the only person that is capable of taking her place and is a really good person, just like Ayu. They are two of the best people in the world IMO.

And I don't think Ayu would mind either, because when they talked on that one show, they got along pretty well and I'm sure both respect each other (which I know Utada does because she said so herself, and I'm pretty sure Ayu does too

) But if Ayu knew Kumi took her place.... >.> UGH! xD But Ayu's not like that, she'd probably just be like "Oh..oh well.."