The first letter is a bit stylized, but given that the rest of the letters are in English cursive, it reads pretty clearly as a cursive N to me. I'm not sure that any of the sources I found are "definitive," but all the random Japanese shop/auction and reference pages that mention the label that I could find (chiefly regarding Yasuhiko Shigemura and Wataru Kuniyasu albums) gave it as either Nadear or ナディア, ex.
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