VY1 (codenamed: MIZKI) is a Japanese VOCALOID developed and distributed by Bplats, Inc., under the YAMAHA Corporation, and was initially released in September 2010 for the VOCALOID2 engine. There has since been a second installment developed for the VOCALOID3 engine and dubbed VY1v3, both products are released in deluxe and standard editions. In December 2014, a third installment was developed for the VOCALOID4 engine and was dubbed VY1v4.
The voice provider for VY1 has never been revealed.
The original VY1 codename for "MIZKI" is a reference to hanamizuki. "Mizki" is often used in error to refer to the VOCALOID or voice by fans of the software. A similar situation same can also occur for VY2 with its codename of "Yuma". Vocadol uses the codename, however, the games content is considered "non-canon".
Unlike past Japanese VOCALOIDs, VY1, along with the voicebank's partner VY2, have never had an official avatar established for them, with the aim of allowing for creative freedom that other VOCALOIDs do not. The character of the VOCALOID was intended to be the producer themselves, rather then the product. 'It' also has no official gender, though the vocal is "female".
The refined version of the character "Kobushi Kiku" from the VesFes contest has been used as a concept for VY1, but has not been established as its official avatar. Other designs used include one for the eVY1 module and a second which was used in the Vocadol game. A further 9 concepts had been originally shown on her release date CD feat. VY1. A total of 12 designs have been used so far to represent VY1's vocal.
Due to the professional design of VY1, the vocal often appears in use for apps and equipment that involves derivative products produced by YAMAHA, either on its own or with VY2.
The standard version of the software has just the VOCALOID2 software included. The Deluxe edition comes with a free CD featuring a number of tracks by different producers, along with the configuration they used for the song and their own interpretation of the VOCALOID. This also provides users examples of how the voicebank could be used as well as offering ideas and suggestions for their own songs. The producers used were already known producers gathered from Nico Nico Douga and YouTube to help demonstrate the new standard YAMAHA hoped to set with VY1.
At VocaFes 2011, two winners were announced whose images will be used for VY1 and VY2. However VY1's redefined version was not presented alongside the original artwork like VY2's was because of an error. Previously, it was announced they would host a competition for everyone to design mascots for the characters as a method of perceiving what the fandom thought of VY1 and VY2.
VY1 was first announced during the time when the focus was on Lily, and comparisons between the reaction in Japan towards Lily and VY1 have been noted and often brought up. Whereas Lily had many songs upon her release, VY1 was apparently slow to gain popularity. Due to its nature, some producers felt it was unemphatic and impersonal.
However over time, VY1's biggest hits in Nico Nico Douga were to come from 'new' producers who had never uploaded a work using 'VOCALOID' before.
VY1 and its following vocal "VY2" were developed to head official Yamaha products. Since their release, the majority of Vocaloid related product produced by Yamaha has included VY1 in the product.
A independent search on Nico Nico Douga revealed that most VOCALOIDs had less then 1,000 videos uploaded on Nico Nico Douga in 2011 between July 1st and December 15th, with VY1 falling into that category as well.
VY1 voiced VOCALO Revolution's introduction and credits, with CUL being the mascot character. Consequently, many fans have confused VY1 and CUL as being the same VOCALOID; as later CUL herself was announced to be released for VOCALOID3. VY1 and CUL (VOCALOID) have no relation whatsoever for VY1 only voices VOCALO Revolution's videos.