Board Thread:Wiki Discussion/@comment-112.209.160.19-20151013132204/@comment-5051846-20151205183217

There hasn't been any official material from Crypton suggesting they are siblings; but feel free to headcanon it as you wish.

CV04 is not confirmed to be Megurine Luka's counterpart; remember that not all Crypton Vocaloids have counterparts. (Only Rin/Len and Meiko/Kaito were designed to sing together. What's to say Miku isn't Luka's counterpart, haha.)