I will be forever shamed if we ever find out that this is Zukki. But while I hear the similarity, I don't think this is Zukki. None of the covers posted, sound definitive enough for me to say "This is Zukki!".
I don't think we'll ever get confirmation. If it is her, she wants to be anonymous, so she'll never say.
For me, I went in thinking "Bah, there's no way this will be Zukki" but by the first line I was sobbing lol. Personally, I'm convinced it's her. Even if it isn't, the videos have made me very happy, so I'll keep following. Just the possibility is enough for me lol
Kasane has posted a comment on her Sailor Moon theme cover - she simply says "I like Mako-chan."
Makoto is the one who wears green.