kokone's release date being Valentine's Day complements the meaning of her name: "heart sound".
She was first announced via Twitter on December 23, 2013 and featured her first demo song. Another tweet confirming her February release soon followed. The vocal was confirmed to be based on a new vocalist.
The next two demo songs were announced to come in mid-January 2014. It was also announced in early January that her boxart would be revealed in the following month.
According to her site , she would also be compatible with the VOCALOID Editor for Cubase NEO.
According to information given before her release, kokone had been in production for 6 months (since July 2013). Originally, Internet co planned a separate falsetto vocal for GUMI, however, switching vocals would prove to be difficult for producers as the tone of voice would be noticed once it switched. When VOCALOID entered the VOCALOID3 era, the falsetto vocal was tested, but it was impossible to hide how noticeable the transition was. The trouble was matching all 50 phonetics from GUMI's normal vocal and her falsetto. The focus of the range would have been to extend GUMI's range beyond F4, giving her the capabilities to reach A3. Instead proceeding with the Megpoid Falsetto vocal, it was decided to create a VOCALOID with both normal and falsetto capabilities built into one vocal: kokone. Most of kokone's production was made in-house.
kokone is a VOCALOID designed to have a large vocal range and produce high quality results. At the time of her release, her vocal range was the largest of any released VOCALOID. kokone is built to handle normal singing vocals, yet smoothly move into falsetto when singing in her higher range. This allows her to act both as a main singer and as a backup singer to other vocals.
The package also contains demo song data and illustrations.
Vocal traits as noted:
Due to the versatile nature of the vocal, kokone can perform a variety of singing roles.
Switching from normal to falsetto is smooth and allows for results not otherwise possible with other VOCALOIDs.
Her overall capabilities are greater even most other individual VOCALOID voices released for VOCALOID™
The vocal is built upon a strong bass.
Her best range is her higher registers, which some find easily display emotion.
She is not designed for any specific genre, allowing for flexibility with the vocal.
Her sounds are clear and smooth.
At at optimum range of #D5, Chika and Kokone have the highest optimum range of any known vocal of VOCALOID3.
At a lowest optimum range of #D2 kokone, V3 Lily, Hatsune Miku V3 vocals Dark and solid as well as Yuzuki Yukari all jointly hold the title of "lowest Japanese female" optimum range between them. They are beaten as overall lowest female by Clara at #C2.
From Ver.4.3.0 of the Vocaloid engine, a XSY group "Internet" was added to Vocaloid. All vocals within the "Internet" group can XSY with each other. This vocal release is part of this group. If a User owns one or more vocals within the "Internet" group, XSY between them will open up as a result of owning this release.
The "Internet" group is currently the largest XSY group. In total if user was to own every VOCALOID3 and VOCALOID4 XSY capable INTERNET co., LTD vocal, this offers the equivalent of 812 additional voicebanks achievable via XSY. The total tone variation offered by the combined packages comes to a theoretical 841 voicebanks in total.
Note that Users of the updated XSY list have to understand that as confirmed by Internet co., Ltd themselves, depending on the combination of the two vocals a level of extra unwanted noise may be generated.
Another note worthy detail on V4 and later vocals compared to V3 vocals within this group is that Internet Co., Ltd. increased the number of triphones from Chika onwards. Thus, many newer vocals do not match sound-for-sound with the older pre-Chika released vocals.
Post VOCALOID4 releases were also developed with XSY in mind, so are better for XSY then the older VOCALOID3 releases.
In addition to not being built with XSY in mind, VOCALOID3 packages with only 1 vocal in their contents that were released may be even more problematic for XSY. Internet co often made multi-pack releases have a quality that made switching mid-song less noticeable between voicebanks, making them slightly better for XSY then single vocal releases.
Note that also "GWL" does not become viable for use with any V3 vocals used as the primarily vocal. This should be considered when using any vocal for XSY within the "Internet" group from V3.
After Otomachi Una, Kokone is the 2nd best choice for XSY as a secondary vocal.
Mostly she is the 2nd best option simply because of the lack of a second vocal compared to Una.
Her vocal range as well as tempo overlap many of other Vocaloids within the "Internet" group.
The attraction to her voice for XSY over Una's is that her voice can be used to lift other Vocaloids towards falsetto ranges that do not otherwise have this capability. Her vocal is therefore capable of adding some significant tone differences to other vocals within this group.
Software issues as noted:
Due to the softness of her falsetto, she produces an unnatural sound on higher registers.
Main voices and falsetto voices have a overlapping range where both can achieve the same notes, as demonstrated by VY2v3's "Standard" and "Falsetto" vocals.
Owed to the fact that kokone has both vocals in the same voicebank, she only sings in one style or the other.
She can switch voice registers in the overlap range without warning, making her unpredictable and sometimes difficult to control.
Editing in an attempt to get the opposite style in this range can leave her sounding unnatural or forced.