アンハッピーバースデイ (UNHAPPY BIRTHDAY)

Background
"UNHAPPY BIRTHDAY" is an original song by Kairiki Bear featuring Hatsune Miku. It was created to commemorate Miku's 10th anniversary.

This song has entered the Hall of Fame. It is featured in Kairiki Bear's album Inai Inai Reboot (イナイイナイリブート).

Concerts
This song was featured in the following concerts.
 * v flower DJ NIGHT (flower's Version)