Yowane Haku (western name order: Haku Yowane) is a Vocaloid created as a derivative of Hatsune Miku. Originally created by artist Caffein, she was meant as a joke to characterize Vocaloid users that created poorly devised songs featuring Miku and then pouted when their efforts were ignored or criticized as being dull. Crypton Future Media, Inc. later recognized Haku as an official Vocaloid, and thus she appears in various marketing and merchandise forms, including as a character in the Project Diva video game series.
Haku does not have an official voice library. Songs sung by her most often use Miku's voice at a lowered pitch. She is generally characterized as introverted and easily depressed; an item commonly associated with her is a bottle of sake.