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.