Board Thread:Poll Archive/@comment-35301431-20141227205446/@comment-11582536-20151229234544

^ Kiyoteru's official birthday is December 4th.

The other two don't have official birthdays, but they were released alongside Kiyoteru on December 4th as well.

(For example of a Vocaloid with different birth/release dates, Iroha's official birthday is different from her release date but I don't remember exactly what it is at the top of my head. I believe Zunko's birthday is also different from her release date.)