Works created to celebrate VocaloidHatsune Miku on March 9th (3/9), also known as Miku Day. Often includes a reference to the date somewhere in the image.
The number 39 is a number pun on both "Thank You" and "Miku" in Japanese.
This tag was previously named MikuPa in reference to "Hatsune Miku's Live Party", a yearly event held on 3/9 from 2011 to 2013 where SEGA and its affiliates put on a giant concert in Tokyo starring Miku.
