In August 2014, along with the announcement of Ryuto's VOCALOID3 update, a new VOCALOID was hinted and was confirmed to be part of the Character Artist Series. Gobou-P confirmed that the voice provider of the new VOCALOID was a member of an old band.
On September 11, the new VOCALOID was introduced in a demo by Peperon-P. Her name was revealed to be Chika and the demo showcased two designs for her: the design used for her boxart and a casual design.
It was announced on September 12 that the voice provider was Chiaki Ito (伊藤千晃 Itou Chiaki), one of the female vocalists of the seven-member Japanese pop band AAA.
According to the website, the first shipped packages of Chika's retail version contained a few extra promotional materials.
Chika is a compact and versatile voice able to fit many genres. Her voice is meant to be cute and firm.
The package also contains demo song data and illustrations.
Vocal traits as noted:
According to Peperon-P, her mid-range is very appealing. He listed D3-G3 as her best range, advising for realistic results not to venture too far from this area.
She has a wide range from bass to treble.
She was designed with any genre of music in mind.
Compared to other vocals, Chika can be used with little trouble - even by beginners.
At higher ranges of #A4 and beyond, Peperon-P notes that she becomes sharper and more huskier sounding, making this range better for high frequency rock music.
Peperon-P also stated that by having largely lower velocity in lower ranges, she can be made to sing ballads.
Can cover rocks songs due to her solid and stable bass.
At at optimum range of #D5, Chika and kokone have the highest optimum range of any known vocal of VOCALOID3.
Once imported into VOCALOID4, she becomes available for XSY.
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.
Phonetic notes as noted:
The length of her consonants is short, which allows her voice to alter quickly and adjust to the melody easily.
Her triphones are longer than normal to give smoother results.
She has 3 newly added phonemes. This did not impact the VOCALOID3 editor as the 3 new sounds were all triphone related.
The vocal itself contains twice the number of phonetic recordings as conventional vocals, resulting in a more natural sounding vocal. This was later confirmed to be caused by the addition of approx 200 triphonetic sounds. Noboru confirmed that she has the most triphones out of their Japanese vocals.
Software issues as noted:
Similarities between Vocaloid voicebanks is nothing new, but Chika is commonly noted for her notorious lack of distinguishing traits between her and other vocals - particularly the past Internet Co., Ltd. package, Megpoid. As a result, there were some issues regarding this package that have been expressed by users that are related to this problem specifically;
Megpoid/Chika share a very similar tone of voice. They have the same tempo range and they almost also share the same voice range; the only difference in their range being that Chika covers 5 more keys than Megpoid does on the higher octave.
As a result of the design, Chika's capabilities were already mostly covered by the existing Megpoid package, who was already much more extensive at this point due to the numerous releases for VOCALOID3.