Internet co noted that they would try to increase triphone numbers and were working to increase the overall performance of their vocals. It was decided to find a second voice provider for the purpose. Due to the fact that the provider of Kaai Yuki would likely be of middle or highschool age, re-sampling her voice for growl samples was a problem. For AH-Software, due to the impact Windows 10 had on maintaining the VOCALOID2 software, AH Software decided to relaunch every VOCALOID2 vocal they had produced as a VOCALOID4 vocal. spoke about the development direction they were taking for the new engine. On November 24, Internet Co., Ltd., AH-Software Co. It was revealed that its release would be on December 17, 2014, with a voicebank upgrade for VY1 also planned. On November 20, YAMAHA made an official announcement regarding VOCALOID4. The new engine's existence was made known in late October 2014. during a discussion about Ruby, a then unreleased English VOCALOID.

VOCALOID4 was first mentioned by Bil Bryant of PowerFX Systems AB.

Vocaloid 4 release