RUBY started as an independent project in December 2013 with only Prince Syo working on her. Half a year later, he was joined by Anders, who had previously worked for VocaTone.Despite Anders helping Syo, a development team did not exist, since Syo exclusively worked on RUBY for the most part.
At some point, Syo searched for companies that could support RUBY and PowerFX, Zero-G and Crypton expressed interest in the project. It became clear that Crypton would not allow much creative freedom at all. Anders thought that Zero-g and PowerFX would be better candidates because he had worked with and trusted them.The two chose PowerFX because they would allow more control over the design.Anders later remarked that at no point was anyone promised any control over the final design and that it was his decision to choose PowerFX.
On September 19, 2014, Syo publicly revealed that he and Anders were working on a VOCALOID and a voice sample of RUBY was posted.At the time, RUBY was affiliated only with VocaTone, but not PowerFX.However, Bil Bryant, the CEO of PowerFX, revealed in October that RUBY would be delayed so that she could be updated to the VOCALOID4 engine.
On October 30, Natasha Allegri posted concept images. It was revealed that she and another artist had been requested to submit concept art for consideration.At the time, it was not confirmed if the concept art would be used in RUBY's final design or whether either of the artists were to be chosen as the final illustrator.
Early in 2015, some early production samples of RUBY were discovered. Syo explained that these test audio clips were not the original uploads of these samples. The originals had been removed and someone else re-uploaded them. However, there was no objection to them existing so long as everyone acknowledged that they were of early versions of RUBY's vocal and that they did not reflect the current status of the project.
It was announced that RUBY would be associated with PowerFX.
Syo expressed a desire to create at least two voicebanks for RUBY to take advantage of VOCALOID4's cross synthesis capabilities, but was unsure due to the doubled workload.The extra workload was owed to the increase in triphonetic data. In addition, PowerFX was only willing to pay for one English voicebank. They wanted to see how well the voicebank sold before adding any additional voicebanks.It was also confirmed that RUBY originally had a Japanese voicebank, but this was scrapped.Her English recordings were redone to sound similar to her Japanese voicebank.
On June 10, Syo asked for original songs that he could use for RUBY demos within a week.Examples had to be sent in and he would decide if the song would be accepted as a demo.
After resolving miscommunication issues with PowerFX, it was confirmed that Natasha Allegri would illustrate the design for the physical copy of RUBY based on the concept Misha, the voice provider, worked on. It took 3 days to produce the art instead of the expected 1–2 weeks.Natasha commented that doing the art made her very happy.
On September 18, Syo tweeted that RUBY would be released within the month.Later that day, he tweeted that the release date of the download version would be the September 23. Boxed versions would be available afterwards.On September 23, it was noted that she was to be delayed.She was officially released as a digital download on October 7.
Her physical version and bundle package were made available on December 12.