Kasane Teto

**Kasane Teto** (重音テト) is a Japanese vocal developed and distributed by AH-Software Co. Ltd., in collaboration with TWINDRILL, and was released as an AI voice database for *Synthesizer V Studio* in April 2023. She was originally released for the *UTAU* engine in April 2008.

She is voiced by the Japanese singer-songwriter and illustrator Oyamano Mayo.

## Concept

Kasane Teto made her debut as a Japanese UTAU who was originally created as a troll "VOCALOID" by fans. She is depicted as more innocent than Hatsune Miku. Teto is cheerful and eager, though may be naughty at times, perhaps inspired by her mischievous roots from Doraemon. She is also depicted as a Tsundere (a mannerism that feigns disinterest to people she is attracted to), but to a gentler extent, unlike the fanmade VOCALOID Akita Neru. Teto hates people who think her pigtails are actually drills. She can also be narcissistic at times and loves getting attention. She gets very angry or sad if someone has bread and does not share it with her. Teto enjoys teasing people just to show she cares about them since she doesn't want to show her love. She can get out of control if not she hadn't eaten bread for a day. There are also persisting rumors of Teto's Chimera alter-ego, giving her wings and a tail. She may or not be aware of her own Chimera form. As for her other skills, she can whip up tricks to extend DVD rentals and her favorite country is Norway.

As a VIPPERloid, "0401" was her ID number, similar to the concept of Crypton Future Media's Character Vocal Series (CV series) VOCALOIDs. This ID number was still referenced in her Synthesizer V version.

### Etymology

Her surname, "Kasane", (重音) means "heavy sound" or "overlapped sound". While these interpretations are widely accepted among fans, TWINDRILL has not released any announcements about the name's meaning. Her given name, "Teto" (テト), comes from "Tetopettenson", a parody song of "Le Beau Tambour". Her name has been officially stylized as "KASANE TETO" and "Kasane Teto".

### Appearance

Teto possesses two main designs: her original design and the 2023 Synthesizer V design. The original design is similar to that of Hatsune Miku, consisting of a dark gray button-up sleeveless shirt, dark gray short pleated skirt, red hanging belt, dark gray detached sleeves, headset, and black thigh-high boots, alongside two light burgundy "drill" twin-tails, commonly called twin drills. She has thick bangs and a red ahoge atop her head. Her eyes are the color of rubies. Her left arm has the text "0401" with "Kasane Teto" beneath it.

Her Synthesizer V design contains many of the same elements but was updated as a cross between a school uniform and a military uniform, giving it an idol look. Her light gray shirt possesses two sets of sleeves, one long and one short, with her right side having another frilled layer above her first short one. The short sleeves have a red border. Her top has black cuffs with red buckles and two rows of gold buttons on the breast. Around the collar is a nameplate with "0401" written. Her light gray, high-waisted skirt has a black fringed petticoat beneath it, and the same hanging belt as her previous design, though this time it attaches to the red hem of her skirt. Both her shirt and skirt depict a set of five lines in various wavelike patterns, reminiscent of a music staff. Her heeled boots are lace-up and mid-calf length, with laces tied around the back. Her left twin-tail has a white ribbon tied in. Teto's nails are painted scarlet.

According to the TWINDRILL livestream after debut, the team revealed some notes about the production of the design:

* Regarding the belt, they were not sure whether to put it inside or outside of her outfit, or if they should include it in place of a tail.
* Since Teto is over thirty years old, the team wondered if the skirt should be lengthened but it was kept short in the final design to give it a cuter look.
* The team was torn on the frill colors of the skirt at first.
* The skirt pattern was meant to resemble a music staff.
* The design looks like a fife and drum corps uniform.
* The team wondered about her having knee-high or short boots in addition to the sock colors.

### Relations

* Utane Uta - Friend. Also known as Defoko.
* Momone Momo - Friend.
* Kasane Ted - Male derivative by pitch manipulation.
* Yokune Ruko - fellow member of VIPPERloid.
* Namine Ritsu - fellow member of VIPPERloid.
* Sukone Tei - fellow member of VIPPERloid.

## Voice Libraries

* Kasane Teto (*UTAU*):

Outdated voicebanks:

* + First voicebanks CV, April 4-13, 2008
	+ Ameya adjusted CV, July 31, 2008
	+ tetovoice-2R6 CV, December 2, 2008
	+ New Lite CV, December 22, 2008
	+ tetovoice Combined version CV, January 20, 2009
	+ New Lite CV 2009 edition CV, October 10, 2009
	+ Experimental VCV, October 20, 2009

Current voicebanks:

* + Extra sounds library, June 19, 2010
	+ Whisper CV, September 25, 2010
	+ CV, April 1, 2011
	+ VCV, April 1, 2011
	+ Whisper VCV, September 17, 2011
	+ Rikimi CV, September 30, 2012
	+ Sakebi VCV, September 30, 2012
	+ English CVVC, April 1, 2015
	+ Weak VCV, October 13, 2018
	+ Edge CV+VV, October 12, 2021
	+ Smooth VCV, November 25, 2021

* Kasane Teto Test Voicebank (*VOCALOID*), Unreleased
* Kasane Teto Talk (*TALQu*), January 8, 2022
* Kasane Teto AI (*Synthesizer V Studio*), April 27, 2023
* Kasane Teto AI Lite (*Synthesizer V Studio*), May 8, 2023

## Additional Information

### Marketing

Following the rising popularity of Hatsune Miku, "Vippers" (Vip News Bulletin@2ch users), the creators behind the VIPPERloid series, schemed a troll "new VOCALOID release" as an April Fool's joke. Sen (線) provided the rough sketch and Nobuyo Oyama (小山 乃舞世 *Oyama Nobuyo*), whose name was a spoof of Doraemon's former voice actress Nobuyo Ōyama (大山 のぶ代 *Ōyama Nobuyo*), provided the vocal. The Teto project continued after the troll campaign, and her vocal was recorded again for use on UTAU, which vocal synthesis software was released two months earlier. UTAU and Kasane Teto were both unnoticed among VOCALOID composers at first, but during the last half of the year of her release, several creators started composing songs for her, causing her fame to be established during the following year. The voice provider's name reading was then changed to Oyamano Mayo (小山乃 舞世 *Oyamano Mayo*) to avoid unnecessary confusion.

Teto had various appearances and merchandise over the years, including albums, figures, live performances, theatre productions, literature, and games (particularly the Hatsune Miku -Project DIVA- series). She was given official acceptance to piapro on April 1, 2010.

Teto's Synthesizer V AI announcement was part of her fifteenth anniversary as an UTAU, making this product her first commercial voice library. The new voice database was promoted on electronic billboards with her own commercial. In addition, an illustration contest ran from April 3 to May 7, which allowed entries featuring the Synthesizer V AI design.

### Reputation

Kasane Teto's character status
**Reaction**

Kasane Teto was one of the most well known Japanese UTAUs, with her popularity rising a year after her release on April 1, 2008, giving her notability as an April Fool's Day joke. As an UTAU, Teto received thousands of original songs, including notable works like "Mimi no Aru Robot no Uta", "Kasane territory ~ Zutto Teto no Turn", "Triple Baka" (featuring the vocals of Hatsune Miku and cameo of the fanloid Akita Neru), and "Horafuki Utahime no Yuutsu". For many years, Teto was mistaken as a VOCALOID at times due to her appearance among them in songs and fanart, and she was also featured in the Hatsune Miku -Project DIVA- series (mainly featuring the Crypton Future Media vocalists in addition to fanloids Neru and Yowane Haku) and the official "Miku Symphony" concert beginning in 2018.

Fifteen years later since her release as a free UTAU, TWINDRILL and AH-Software announced that Kasane Teto would be releasing as a commercial Synthesizer V AI library scheduled for April 27, 2023, which sparked much support and celebration from her long-time fans and producers from all around the world. The reaction from overseas fans especially was bigger than the team expected. The team also expressed anxiety that fans might not like the sound of Teto's Synthesizer V AI version, but they were pleased to learn that many fans thought that she still sounded like herself. In addition, the TWINDRILL team was surprised to see how fast people made fanart of Teto's new design, especially since the outfit was considered complicated. The official TWINDRILL Twitter account also gained 3,000 new followers after the announcement. During her pre-order period, AH-Software had noted that Teto had been a very popular purchase.
**Miscellaneous**

* Kasane Teto's Synthesizer V AI was announced and promoted in celebration of her 15th anniversary since her release on UTAU.
* Teto's ID number, 0401, is likely a reference to April 1, her UTAU release date.
* Teto is a part of the Kasa-Ama-Nago (重(かさ)天(あま)和(なご)) unit also known as Double Yakuman (だぶるやくまん) alongside Amane Luna and Nagone Mako.
	+ Double Yakuman is a reference concerning Mako and Luna's duo unit, Tenhou. Both are references to mahjong terms.
* The first song featuring Teto's Synthesizer V voice database to reach 1 million views was a cover of "Idol" created by Mikage Shii, which occurred on May 12, 2023. The first original to reach 1 million views was "BABEL" by Iyowa which was achieved on June 16, 2023.

**Achievements**

* First Synthesizer V from TWINDRILL
* First female Synthesizer V from TWINDRILL

## References

1. ↑ Q&A 性別がキメラってどういうこと？
What does "gender: chimera" mean?
2. ↑ Q&A テトは本当に31歳なの？人間に直すと年齢は半分になるの？
Is Teto really 31 years old? Should her human age be counted by half?
3. ↑ Q&A 重音テト制作時に参加者の一人から提案されて採用された苗字ですが、その由来は不明です。
(This is) a surname suggested by a vipper (denizen of vip@2ch) and we adopted it, but where this name was from is not clear.
4. ↑ 4.0 4.1 https://www.youtube.com/watch?v=k-tMiZmwLvY
5. ↑ "Synthesizer V AI Kasane Teto Announced by AHS and Twindrill" - a summary and translation of Kasane Teto's debut contents by MARUMAIN
6. ↑ https://kasaneteto.jp/history/ongen\_rekishi.html
7. ↑ https://twitter.com/twindrill\_teto/status/53518313401221120
8. ↑ https://twitter.com/twindrill\_teto/status/53518313401221120
9. ↑ https://twitter.com/twindrill\_teto/status/115405334994108416
10. ↑ https://twitter.com/twindrill\_teto/status/254521479465668608
11. ↑ https://twitter.com/twindrill\_teto/status/254521479465668608
12. ↑ https://twitter.com/twindrill\_teto/status/1642745949536817155
13. ↑ https://www.youtube.com/watch?v=5yxxqnzcwB0
14. ↑ https://www.pixiv.net/contest/teto15th\_anniv
15. ↑ https://twitter.com/twindrill\_teto/status/1642754783277891585
16. ↑ https://twitter.com/twindrill\_teto/status/1643063982243344384
17. ↑ https://twitter.com/ahsoft/status/1648929840047980546
18. ↑ https://dic.nicovideo.jp/a/%E3%83%80%E3%83%96%E3%83%AB%E5%BD%B9%E6%BA%80
19. ↑ https://www.youtube.com/watch?v=qObmE2YRA7s