On July 12, 2018, four vocals were introduced upon the release of VOCALOID5. Amy is the English female vocal, Chris is the English male vocal, Kaori is the Japanese female vocal, and Ken is the Japanese male vocal. They come with the software no matter which version the user purchases: "Standard" or "Premium".
The 4 vocals act as "starter" vocals and are acquired upon the purchase of VOCALOID5 regardless if the user buys the "Standard" or "Premium" versions. This is the first time since VOCALOID2 a release has been only available with a major engine release, though the first ones to only be included with need to buy the engine once.
The package is split between an English and a Japanese male/female pair. These vocals act as a new "Standard" for VOCALOID.
Vocal traits as noted:
Potentially, the user does not need to buy any other additional voicebank as a result to get started with VOCALOID. This is different to past versions of VOCALOID, VOCALOID3 and VOCALOID4, where the engine came with no additional vocalists resulting in the purchase of further vocals.
As per expected, their sample quality is high, clean and clear.
They work well with all the new Vocaloid5 features and their vocals can easily morph to demonstrate the styles and colour options.
Users always have access to both the English and Japanese languages upon installation. This is the added bonus of allowing users to experiment to see which language they feel most comfortable to work with. Previously the only way to experiment with both English and Japanese vocals was to buy separate vocalists in both languages or to buy bilinguals with one option being expensive to purchase and the other option always having 1 language that turned out weaker then the other due to the second language being voiced by a non-native.
As noted by the Yamaha VOCALOID5 English tutorial, the Japanese vocalists are both a little more precise when singing Japanese phrases. This is mostly expected due to the English language being hard to recreate.
The English vocals have on several occasions been noted for their parallels to the very first VOCALOIDs, released LEON and LOLA for the VOCALOID engine, by fans. This is not just in how they sound, but their vocal type and genres of music they cover.
Software issues as noted:
Upon their release, there were no guidelines to aid a producer in using any of the 4 vocalists, leaving the user blind in having to find out the vocalists' best results through trial and error. This is not a first for VOCALOID, however it is not common practice since VOCALOID2.
There are issues with including them with VOCALOID5. Not all users can work with languages they are not familiar with. This means the user may be left with 2 vocalists at least they never wanted or can't use beyond basic sound samples.
For users of the other 3 languages VOCALOID has produced (Spanish, Chinese and Korean), potentially all 4 voicebanks could prove to be not useful at all.
Due to being included with the VOCALOID5 engine, this makes them some of the most expensive vocals to purchase.
The main reason they are so expensive simply is because they come with the VOCALOID5 engine. In past VOCALOID and VOCALOID2 versions, as well as all packaged VOCALOID3 and VOCALOID4 versions wherein the engine was bungled with the voicebank, the price was generally higher for joint voicebank and engine. There is no way to gain access to their vocals without the engine.
However, based on past engine prices for VOCALOID3 and VOCALOID4 (which were set at a approximate price of $95), if this was used as an estimated price for the engine and the total cost to buy the Standard version, the 4 are still being sold quite cheap at another approximate estimated price of $220.
This is the second best deal that VOCALOID offers: 4 vocals across two languages with 4 different vocalists behind the release. The best option would be buying the full Premium version of VOCALOID5 which includes the VY series for an additional $129 price.
The 4 have issues with variable levels of roboticness. Though this is common among Vocaloid and vocal synthesizers in general, for them is noticeable.
If the user has the Premium alone, then it can easily be observed how all 4 VY series vocals out class Amy, Chris, Kaori and Ken in terms of natural sounding vocals. All 4 VYs generally sound better then their newer counterparts and perform better.
Ken is a Japanese-capable male designed to be a "standard" vocal for VOCALOID5.
Vocal traits as noted:
He has a soft tone, but is a little nasally at times.
Ken is the default vocal for VOCALOID5 and the engine will always revert back to his voicebank if an issue occurs, though this can be changed to other vocalists if the user doesn't want him to be the default vocalist.
He is sharp and clear making him ideal for J-pop.