Board Thread:Questions and Answers/@comment-24527167-20141219012348/@comment-32500188-20141219020309

Pretty much the answer is this: The free upgrade is only available to those who are both Japanese nationals and have purchased from a Japanese distributor, as well as attach a receipt for proof of purchase. There's no word of this becoming available to anyone outside of Japan as of yet.

However, the prefered upgrade (which is a discounted price for those who have purchased the V3 editor before November 9, 2014 and have a valid license key) can be purchased by anyone if they buy it through the Japanese VOCALOID store.

Hope that answers your question. (^-^)