This is an article about the Kizuna Akari software for the VOCALOID4 engine.


While celebrating the 5th anniversary of Yuzuki Yukari it was mentioned that the notion of making the next vocal was brought up. Having released all the planned vocals for Yukari both in Vocaloid and Voiceroid, the issue became a more serious one. Bumpyうるし mentioned in an interview that he had been wanting to do the next vocal for some time, but focus was always on expanding the Yukari vocal before then.[1]

Akari was a secret project and nothing was ever shown to the public. Each member of the team worked independently, bringing in voice actors and singers to interview, eventually resulting in 10 candidates. They noted, as the character and voice would grow, this would be a long term relationship between the team and the candidate. Ah Software provided advice, songs were recorded in the voice and tested to see how they sounded. The audition took 3 days to carry out, resulting in a 4 day session. Though they knew what they were after no on-the-spot decisions could be made.[1]

Temporary voicebanks were made, these have been known to occur in the past with other Vocaloid developments and act as tests on how a voice fairs within the Vocaloid software. Both Vocaloid and Voiceroid were sampled at the same time to make a overall judgement of the voice. Since Ah Software had 7 years of experience of Vocaloid and Voiceroid by this point, the process was fairly efficient overall.

From the beginning it had to be made clear Akari was a different vocaloid to Yukari. When provisionary voicebanks was made, demo songs were also produced to help the evolution of the development of the Vocaloid along, though ideas had started to form such as titles. When everyone's opinions were gathered, a overall decision was made on things. As with Yukari before her, Akari's voice was made before they even considered the character itself.[1]

The illustrator wasked if they could do the same as they had done with Yukari for Akari's artwork. Listening to the voice of the character, and seeing the characters side by side, the name was picked out about this time. Since Yukari was based on the moon, they kept the astrological thing discussing on if Akari should be based on the sun or stars. The name had to hold a story behind it. "紲" meaning "Bond" was problematic for them because it could be mistranslated to "tying people" and they also considered forcing the word "Star" into the name itself. Eventually they decided on on a name.[1]

Development of the Voiceroid and Vocaloid took place during this, with the Voiceroid recording session taking 2 days and being done in a method that resembled the provisionary voicebank for Vocaloid. Vocaloid, though already one step ahead the Voiceroid, took a further 6 days to record, this is why the Voiceroid was released ahead of the Vocaloid voice. Another day was taken to record exVoice samples for both. It was originally intended for the two to be released on the same day, but the Vocaloid was taken far longer to produce, being 4 months behind her scheduled release of her Voiceroid. Speaking on the exVoice, the issue with Vocaloid is that consonants feel weak at times or cannot produce alternative consonants. The exVoice for her Vocaloid release is intended therefore to be able to be copied and pasted on the sound track in place of Vocaloid alternatives.[1]

On November 30, 2017, Vocalomakets and AH-Software Co. Ltd. revealed a new character to be added to the VOICEROID2 line: Kizuna Akari. Her VOICEROID2 product was set to be released on December 22 that year. It was also mentioned that they were working diligently on her VOCALOID version at the time. Juu Ayakura was confirmed to be the illustrator for Akari, but her voice provider was not to be revealed until the VOCALOID package was released.[2] Vocalomakets later tweeted that there is no information about Akari's relation to her predecessor, Yuzuki Yukari, and only confirmed parts of her biography.[3]

On December 17, Vocalomakets hosted a livestream featuring new Yuzuki Yukari merchandise and three Akari VOCALOID demos. It was revealed that Akari also has exVOICE files and that she was expected to release in 2018.[4]

On March 29, 2018, Akari's preorder period was launched. It was revealed that Akari would be available as an individual pack (physical and digital copies), a starter pack, and a dual pack with Yukari. Her release date was confirmed to be April 26, 2018.[5]

On April 13, Akari's trial was made available.[6]

On June 3, Akari's voice provider was confirmed to be Madoka Yonezawa.[7]

Product InformationEdit



Sprites!☆ Niconico YouTube SoundCloud
リナリア (Linaria) Niconico YouTube
あなたと二人で (Anata to Futari De) Niconico YouTube
exVOICE Examples Niconico YouTube
パニジャパーの奇跡 (Panijapaa no Kiseki) Niconico YouTube SoundCloud
星のオーケストラ (Hoshi no Orchestra) SoundCloud
オリオンに願いを (Orion ni Negai o) SoundCloud


  • OS:
    • Windows: Windows 8.1, Windows 8, Windows 7 (32/64bit)
    • Mac: OS X 10.8 (or later)
  • CPU: Intel Dual Core CPU
  • RAM: 2GB or more
  • Hard Disk Capacity:
    • Standalone package:
      • More than 1.5GB (using VOCALOID4 Editor)
      • More than 9.5GB (using VOCALOID4 Editor for Cubase + Cubase)
    • Starter Pack: More than 1.65GB (using VOCALOID4 Editor)
    • Yukari and Akari dual package
      • More than 2.5GB (using VOCALOID4 Editor)
      • More than 10.4GB (using the VOCALOID4 Editor for Cubase + Cubase)
  • Internet connection.

Voicebank LibrariesEdit

Product Information
  Optimum Tempo: 70 ~ 190BPM  Optimum Range: G2 ~ A4[8]
  Total Tempo (min-max): 120BPM  No. of Keys: W=16,B=11,Total=27
  Trial/Demo Vers?: Yes  Starter Available?: Yes
Package details
Akari is intended to sound kind and gentle with the intention to portray a cute, bright female voice and under the theme of "starlight".

Her package also comes with an "exVoice" set. There is a voice release for VOICEROID2.

Vocal traits as noted:
  • She is able to sing a side range of genres from rock to pop.
  • While Yukari is meant to be an adult voice, Akari is a more cutesy vocal with a lighter tone then Yukari.[1]
  • At 70bpm, Akari can handle slow songs relatively well, just not as well as Yukari at 60bpm and there are a few genres of music that Yukari still can handle better than Akari.
  • Her tempo range is superior overall then Yukari's and is double the size range. As a result, she can tackle far more genres of music than Yukari.
  • Aside from the slower song genres Yukari can cover, Akari covers all of Yukari's tempo range and has a superior range in total.
  • Akari sounds best when going from low to high.[1]
  • The team behind her feel she is good for beginners.[1]
Cross-Synthesis notes:

This vocal will register for XSY, however this is a single release voicebank and there are no additional vocals included for her to utilize this function. Therefore users will have to purchase addition voicebanks not belonging to Akari at all for use of XSY from her XSY group "AHS".

  • From Ver.4.3.0 of the Vocaloid engine onwards, a XSY group "AHS" was added to Vocaloid. All vocals within the "AHS" group can XSY with each other. This vocal release is part of this group. If a User owns one or more vocal releases within the "AHS" group, XSY between them will open up.[9][10]
    • The group has 8 characters within it that can XSY; Yuzuki Yukari, Macne Nana, Macne Petit, Tohoku Zunko, Hiyama Kiyoteru, Nekomura Iroha, SF-A2 miki and Kizuna Akari.
    • The "AHS" group is currently the second largest XSY group within Vocaloid, having a total of 14 voicebanks that can XSY with each other. If old versions that have since been re-released are removed, there are currently 12 unique voicebanks. These are; "Yuzuki Yunki Jun", "Yuzuki Yukari Onn", "Yuzuki Yukari Lin", "SF-A2 miki", "Tohoku Zunko", "Macne Nana","Macne Petit", "Kitzuna Akari", "Hiyama Kiyoteru natural", "Hiyama Kiyoteru Rock", "Nekomura Iroha natural" and "Nekomura Iroha soft".
    • In total if user was to own every VOCALOID3 and VOCALOID4 Ah software vocal within the "AHS" group, this offers the equivalent of 182 additional voicebanks achievable via XSY. The total tone variation offered by the combined packages comes to a theoretical 196 voicebanks in total.
  • 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 "AHS" group from V3.
  • Also note that the updated vocals that brought a Vocaloid from VOCALOID3 into VOCALOID4 provided few differences, aside from adding GWL. Therefore these updates can provide little difference when used for XSY.

Voicebank sample

Kizuna Akari VOCALOID4