Natsuki Karin (Synthesizer V Studio)

* Physical
* Digital

* AHS Store
* AHS Store (user discount)
* Amazon
**Digital copies**:

* AHS Store
* AHS Store (Starter Pack)
* AHS Store (Starter Pack; user discount)
* animate GAMES
* DLSite
* Dwango JP Store
* SONICWIRE
* Vector PC Shop
**Lite versions:**

* AHS
* Dreamtonics

**This article is about the Synthesizer V Studio software known as a voice database. If you are looking for the Synthesizer V character then click here.**

## History

Originally, Natsuki Karin and Hanakuma Chifuyu's voice synthesizer production announcement was meant to be announced during Koharu Rikka's first live concert, "Koharu Rikka 1st LIVE! First Day of School!", in Fall 2020. However, because the concert was postponed due to the COVID-19 pandemic, the pair's production was unannounced.

### 2021

Natsuki Karin was introduced in a campaign titled "Koharu Rikka x Otaru Collaboration (小春六花×小樽コラボ)" on May 22, 2021. She was confirmed to be a student enrolled at the fictional Otaru Shiokaze High School and was in the same music club as Koharu Rikka. Details about Karin as a character were released and she was confirmed to be voiced by Miyu Takagi for a promotional video. She was illustrated by Teshima Nari and the logo was created by Hiroaki Watanabe. It was noted in a TOKYO6 ENTERTAINMENT livestream that there were plans to create a voice library for Karin and Hanakuma Chifuyu, which were confirmed in June to be Synthesizer V AI and CeVIO AI after TOKYO6 ENTERTAINMENT adjusted their website.

On August 8, due to some concerns regarding business activities related to Synthesizer V, Dreamtonics Co., Ltd. noted that Karin was on the list of "yet-to-be-published" voices and initiatives. For many overseas fans, this was the first time they became aware of these voice databases as there was no official announcement via social media, newsletter, or website adjustments regarding the productions. Due to language barriers, the livestream featuring the announcement was overlooked. On September 30, a livestream was confirmed to begin on October 3.

On October 3, it was confirmed that Karin would be produced as the second TOKYO6 character to release. Demonstrations of her Synthesizer V AI and CeVIO AI voice databases, along with a set of Pitagoe samples, were released in addition to an announcement of her crowdfunding campaign, which was set to begin on October 8 and would run until October 28. Separate illustrations for Karin's Synthesizer V and CeVIO designs were also revealed. Karin was expected to release in April 2022.

On October 8, Karin's crowdfunding campaign was launched with a goal of 6,800,000 yen. The main goal was reached in less than three hours since launch, then the final stretch goal was reached on October 11.

### 2022

During the AH-Software Co. Ltd. live broadcast on February 17, 2022 (where TOKYO6 acknowledged their cooperation in the development of VOICEPEAK, AH-Software's new text-to-speech software based on Dreamtonics' Syllaflow AI speech-synthesis engine), Natsuki Karin's release month was reconfirmed to be April. Also, Karin's voice provider Miyu Takagi was confirmed to be making a guest appearance on March 25's AHS livestream.

On March 24, it was announced that Karin would be releasing for CeVIO AI and Synthesizer V AI on April 13 as physical and digital copies. She was also confirmed to be available for the AH-Software starter pack. Details about her voice were provided and pre-orders were launched, and a lite version of her voice database was expected. Crowdfund backers for Karin were to receive her in early April. On March 26, the release of Synthesizer V Studio version 1.6.0 brought new features: Vocal Mode and Instant Mode. TOKYO6 announced that these features would be brought to Rikka and Karin later due to the need of making adjustments to the voice databases.

Karin's Synthesizer V AI voice database and CeVIO AI Talk Voice were released to crowdfund backers on April 1; other crowdfund rewards were also being delivered. Karin was released on April 13 as expected for both voice synthesizers. The Lite voice database was released later in the day at 12:00 JST.

On July 21, Karin was one of the AI voice databases to receive an update for HDVM compatibility (a feature introduced in Synthesizer V Studio Pro 1.7.0, also released the same day), as well as giving Karin access to five new vocal modes, including: Kawaii, Soft, Cool, Happy, and Falsetto, respectively, that had previously been teased about four months prior.

However, some users complained about unstable voice-quality results when re-rendering in 1.7.0 projects saved under earlier versions of the editor that made use of her voice database (after updating it to v104). On July 22, Dreamtonics explained that by default, the AI Retakes feature favors "rich timbre and expressions over smooth and stable vocalization", resulting in inconsistent behavior relative to previous versions; as a workaround to stabilize the voice output, both Dreamtonics and AH-Software offered these steps below:

* Empty the selection.
* Open AI Retakes panel, go to Timbre tab.
* Under Takes -> Global Settings, reduce Expressiveness.

Responding to requests from users, both Dreamtonics and AHS made available for download that same day rolled-back versions of Natsuki Karin (as well as other affected AI voice databases distributed by them) by logging in to their respective websites. However, it was also noted by AHS that, even after removing HDVM compatibility, voice quality for Karin was still affected by AI Retakes which was not supported in the then-available rollback version.

An update for Karin was announced on October 14. TOKYO6 ENTERTAINMENT would like to implement it as soon as possible, but it still needed time. On November 14, after the release of Karin's v106b1 installer, TOKYO6 ENTERTAINMENT released a survey for its feedback. On November 22, the company noted that the beta version would be used as the official update after receiving mostly positive feedback.

### Updates

Natsuki Karin v104 - July 21, 2022
A free update for Natsuki Karin was released following the Synthesizer V Studio 1.7.0 update. This enables her to use the new High Dynamics Voice Models and AI Retakes features, as well as giving her access to the Vocal Modes feature from the 1.6.0 update. Her Vocal Modes are named Kawaii, Soft, Cool, Happy, and Falsetto.

Natsuki Karin v102 - July 22, 2022
A free downgrade for Natsuki Karin that removes HDVM compatibility, but retains the Vocal Modes introduced in v104.

Natsuki Karin v101 - July 25, 2022
A further downgrade which removes all new features except for Vocal Modes; described by TOKYO6 as "Release Version + Vocal Modes". It was issued when AHS reported TOKYO6 that v102 was still affected by the new features introduced in Synthesizer V Studio 1.7.0 that affected pronunciation.

Natsuki Karin AI v106b1 - November 10, 2022
A free update for Natsuki Karin was released following the Synthesizer V Studio 1.8.0b1 update. This enables her to use the new Diffusion Probabilistic Models (DPM) feature.

Natsuki Karin AI v106 - November 24, 2022
Final version update compatible for Synthesizer V Studio 1.8.0 and enables Natsuki Karin to use the new Diffusion Probabilistic Models (DPM) feature if the beta version was not installed previously.

Natsuki Karin AI v107b1 - June 21, 2023
A free update for Natsuki Karin was released following the Synthesizer V Studio 1.9.0 update. This implemented the new rap feature available for the English and Mandarin languages. Cantonese Chinese was added to the Cross-lingual Singing Synthesis feature as well as general improvements to the overall function, resulting in more accurate pronunciation that sounds closer to a native speaker when singing foreign words.

Natsuki Karin AI v107 - July 6, 2023
Final version update compatible for Synthesizer V Studio 1.9.0 and enables Natsuki Karin to use the rap feature (English and Mandarin Chinese only) and allow for Cantonese Chinese Cross-lingual Singing Synthesis if the beta versions were not installed previously.

Natsuki Karin AI v108b1 - August 2, 2023 A free update for Natsuki Karin was released following the Synthesizer V Studio 1.10.0b1 update. This enhanced pitch generation by utilizing Reinforcement Learning from Human Feedback (RLHF), translating to fewer off-key errors, making better use of vibrato, and creating more expressive transitions between notes. This also allowed for the use of the new "Enhancement" slider in the AI Retakes panel, which controlled the level of changes introduced by RLHF. For Synthesizer V Studio Pro users, feedback submission was enabled, allowing users to consensually share their preferred takes with only Dreamtonics for research and development purposes, where models trained with this feedback would be deployed in future voice database updates. Users may also opt out of this feature if undesired.

Natsuki Karin AI v108b2 - September 28, 2023 A free update for Natsuki Karin was released following the Synthesizer V Studio 1.10.0b2 update, which was the second beta version following version 1.10.0b1 that introduced enhancements to voice databases and integrated the latest user feedback via Reinforcement Learning from Human Feedback (RLHF). Regarding the editor, numerous reported issues were addressed for a more fluid experience. A new generation of pitch models were trained using the extensive feedback from users over the past month, and the new models offered greater accuracy in voice timbre reproduction, as well as a reduction in mispronunciations. Dreamtonics also focused on issues from the previous beta release that made Vocal Modes seem less distinct on certain vocals, ensuring clearer differentiation in the 1.10.0b2 update. The latest update also introduced a new feature in the Note Properties Panel that allowed for even division of a note into multiple syllables, proving to be a useful tool for songs with faster tempos.

## Voice Database Information

### Voice Databases

Product Information
**Optimum**

  **Genre:** Pop, Rock  **Range:** G3 ~ C6
**Versions**

  **Lite Version/FLT Available?:** Yes (Lite)  **Starter Pack Available?:** Yes  **Web Version Available?:** No
**Package details** as noted:

Natsuki Karin is a feminine Japanese voice database that is designed to be suitable for all genres but especially excels in pop and rock. She was noted to have a wide vocal range and a stable high note. As expected of an AI voice database, this enables her to sing with a more human-like and realistic voice. Her voice database is based on the singing style of Miyu Takagi.
**Vocal traits** as noted:

* Similar to her voice actress, Karin has a clear and high tone.
* Karin has a cute voice but her low notes have a slightly mature tone.
* She has a voice that is not easily drowned by intense instrumentals, making her a preferable voice for producers specialized in hard rock and metal genres.
* As per the Synthesizer V Studio 1.7.0 update launched on July 21, 2022, through High Dynamics Voice Models (HDVM), which later migrated to Diffusion Probabilistic Models (DPM) per the 1.8.0b1 update on November 10, AI voice databases may use AI Retakes to create multiple "takes" of a sung section with variations in pitch, dynamics, and timbre. This replicates the randomness of human vocalists, adds a more realistic feel, and allows users to find an ideal vocal without the need for "laborious tuning." This feature is only available in the Synthesizer V Studio Pro Editor.
* This does not apply to the Lite version.

**Phonetic notes** as noted:

* Phoneme format: Romaji
* Through cross-lingual singing synthesis, Karin is able to sing in not only Japanese but also in English and Mandarin Chinese. Since the release of her v107b1 update on June 21, 2023, she can also sing in Cantonese Chinese with this feature. Cross-lingual Singing Synthesis is only available in the Synthesizer V Studio Pro Editor.
	+ This does not apply to the Lite version, thus restricting the voice database to Japanese only.
* Downloadable Pitagoe voice files are available for those with Karin's CeVIO AI Talk Voice or Synthesizer V AI voice database after user registration on AH-Software's website. There are over 900 audio files, including ASMR, to use for a wide variety of genres.
	+ List of recorded audio
		- Talk Pitagoe
		- ASMR Talk Pitagoe
		- Song Pitagoe
		- ASMR Song Pitagoe
	+ On April 4, 2022, AH-Software announced that some of the file names were garbled for the Pitagoe voice. A modified version was released to correct these.

**Vocal Modes** as noted (Synthesizer V Studio Pro Editor only):

* As of July 21, 2022, the paid version of Natuski Karin became compatible with the Vocal Mode function introduced in Synthesizer V Studio 1.6.0. Her v104 update included five variations:
	+ "Kawaii"
	+ "Soft"
	+ "Cool"
	+ "Happy"
	+ "Falsetto"

**System requirements** as noted:

	+ Intel Core series 4th generation i5 (i5-4xxx) or higher
	+ AMD Athlon X4 845, Ryzen series or higher
* RAM: 2GB or higher
* Disk Space: 1 GB or higher (for installing one voice database)
	+ The amount of space required depends on the number of voice databases installed.
* Display: 1280 x 800 or higher

	+ Windows 11/10/8.1
	+ Mac OS X: 10.11 or higher
	+ Linux Ubuntu 18.4 or higher

**Other:**

* DVD-ROM Drive (physical edition only)
* Sound card
* Internet connection is necessary for activation and obtaining updaters.

**License agreements** as noted:

* TOKYO6 ENTERTAINMENT's Character Usage Guidelines - Japanese
* AH-Software's End User License Agreement - Japanese
* AH-Software's End User License Agreement - English
* Regarding the Lite version:
	+ AH-Software does not accept technical inquiries regarding free software nor do they guarantee or support the operation of all free software.
	+ AH-Software is not liable for any damages (including loss of data) caused by using free software. Users are cautioned to use the free software at their own risk.
	+ The program may not be transferred, sold, lent, distributed or rented without AH-Software's permission, regardless of whether it is paid or free of charge.
	+ Reverse engineering, including modification, decompilation, and disassembly, of their program for any purpose is prohibited.
	+ Natsuki Karin Lite may not be used commercially in any way
	+ When using the Lite version of this voice database, "This work uses the Lite version" must be mentioned on any uploads.

**Voice database sample**

## References

1. ↑ 1.0 1.1 1.2 1.3 https://www.dtmstation.com/archives/60921.html
2. ↑ https://twitter.com/tokyo6info/status/1396090971088211973
3. ↑ https://twitter.com/tokyo6info/status/1396092229597470723
4. ↑ https://twitter.com/tokyo6info/status/1396092229555470337
5. ↑ https://note.com/tokyo6/n/nc5e32c933fa1
6. ↑ https://twitter.com/tokyo6info/status/1396092481008066565
7. ↑ https://www.youtube.com/watch?v=M9wDSETvuzY
8. ↑ https://twitter.com/dreamtonics\_en/status/1424533859752812545
9. ↑ https://twitter.com/tokyo6info/status/1443499343445594117
10. ↑ https://twitter.com/tokyo6info/status/1444648429351800841
11. ↑ https://twitter.com/\_17meisai23/status/1444654409766498315
12. ↑ https://www.youtube.com/watch?v=MskBg1dEGW4
13. ↑ https://twitter.com/rikka\_info/status/1446445271399944192
14. ↑ https://twitter.com/tokyo6info/status/1447492290834944002
15. ↑ https://twitter.com/tokyo6info/status/1494296032750219267
16. ↑ https://twitter.com/tokyo6info/status/1494298937528053760
17. ↑ https://www.ah-soft.com/press/cevio/20220324.html
18. ↑ https://twitter.com/ahsoft/status/1506831478369714186
19. ↑ https://twitter.com/tokyo6info/status/1506834090401869824
20. ↑ https://twitter.com/tokyo6info/status/1507669520500273153
21. ↑ https://twitter.com/karin\_info1/status/1509809811395059712
22. ↑ https://twitter.com/karin\_info1/status/1513923454067949572
23. ↑ https://twitter.com/ahsoft/status/1514077001103319046
24. ↑ https://twitter.com/dreamtonics\_en/status/1550050403613835264
25. ↑ https://twitter.com/tokyo6info/status/1507669520500273153
26. ↑ https://twitter.com/dreamtonics\_en/status/1550520904291012609
27. ↑ https://twitter.com/dreamtonics\_en/status/1550520905868009472
28. ↑ https://twitter.com/ahsoft/status/1550385484027035649
29. ↑ https://twitter.com/dreamtonics\_en/status/1550520907159851009
30. ↑ https://twitter.com/ahsoft/status/1550385686389616640
31. ↑ https://twitter.com/ahsoft/status/1551766239516979202
32. ↑ https://twitter.com/s\_akasakov/status/1580837785623142401
33. ↑ https://twitter.com/tokyo6info/status/1591981747180163072
34. ↑ https://twitter.com/tokyo6info/status/1594852826085494784
35. ↑ https://dreamtonics.com/en/synthesizer-v-studio-1-7-0-update-ai-retakes-feature/
36. ↑ https://twitter.com/tokyo6info/status/1550387952882450432
37. ↑ https://twitter.com/tokyo6info/status/1551769998216966144
38. ↑ https://twitter.com/ahsoft/status/1551774834983866368
39. ↑ https://dreamtonics.com/en/synthesizer-v-studio-1-8-0b1-update/
40. ↑ https://dreamtonics.com/en/synthesizer-v-studio-1-8-0-final-update/
41. ↑ https://twitter.com/ahsoft/status/1595674717200916481/
42. ↑ https://dreamtonics.com/synthesizer-v-studio-1-9-0-final-update/
43. ↑ https://twitter.com/dreamtonics\_en/status/1671427830629154816
44. ↑ https://www.bilibili.com/read/cv24826703/
45. ↑ https://twitter.com/ahsoft/status/1676865674898206720
46. ↑ https://twitter.com/dreamtonics\_en/status/1686648078571655168
47. ↑ https://t.bilibili.com/825177687051993121
48. ↑ https://dreamtonics.com/synthesizer-v-studio-1-10-0b1-update-enhancing-pitch-generation-with-user-feedback/
49. ↑ https://twitter.com/ahsoft/status/1686653272474738689
50. ↑ https://twitter.com/dreamtonics\_en/status/1707304150059639108
51. ↑ https://dreamtonics.com/synthesizer-v-studio-1-10-0b2-update/
52. ↑ https://twitter.com/ahsoft/status/1707304906535956719
53. ↑ "Yīshēng zhī Xìng" was meant to demonstrate Mandarin Chinese Cross-lingual Singing Synthesis, but the language setting was still set to Japanese
54. ↑ https://dreamtonics.com/en/synthesizer-v-studio-1-8-0-final-update/
55. ↑ https://twitter.com/dreamtonics\_en/status/1550048543624564736
56. ↑ https://twitter.com/dreamtonics\_en/status/1550048543624564736
57. ↑ https://twitter.com/tokyo6info/status/1510290073253969921
58. ↑ https://twitter.com/ahsoft/status/1510829159211503616