Kasane Teto 《Brainrot》

Main Info: Kasane Teto (重音テト) is a Japanese (and later English) UTAU who was originally created as a troll "VOCALOID" by fans. Her surname 重音 (Kasane) literally means "heavy sound" or "overlapped sound;" while these interpretations are widely accepted among fans, TWINDRILL has not released any announcements about the meaning of the name. Her name テト (Teto) comes from Tetopettenson, a parody song of Le Beau Tambour. Although her original voicebank was only for use in UTAU, many people still mistook her for a VOCALOID (and still mistake her for one to this day). Though she had no final voicebank released for the VOCALOID engine, there were attempts in 2012 to release Teto for VOCALOID in collaboration with AH-Software Co. Ltd., and she later had a private beta voicebank with Crypton Future Media, Inc. in 2017. She later released as a speech voicebank for the TALQu text-to-speech synthesizer in January 2022, an AI singing voice database developed by AH-Software for Synthesizer V Studio in April 2023, and an AI text-to-speech voice library also by AH-Software for VOICEPEAK in April 2025.

Race: Chimera (she has bat wings)

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".

History: Teto is held under license by Team TWINDRILL and usage of her image and voicebank must comply with their licensing agreement. Her initial release is BOUCALOID on April 1, 2008 with triphones on September 17, 2011, and her second release is BOUCALOID APPEND on October 1, 2012. Following the rising popularity of Hatsune Miku, "Vippers" (Vip News Bulletin@2ch users) schemed a troll "new VOCALOID release" as an April Fool's joke. Sen (線) provided the rough sketch and Nobuyo Oyama, a spoof for Doraemon's former voice actress Nobuyo Oyama, provided the vocal. The Teto project continued after the troll campaign, and her vocal was recorded again for the use on UTAU, which vocal synthesis software was released two months earlier. UTAU and 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 Teto, causing her fame to be established during the following year. The voice provider's name reading was then changed to Mayo Oyamano (小山乃 舞世 Oyamano Mayo) to avoid unnecessary confusion. Teto was given official acceptance to piapro on April 1, 2010, and to Project DIVA on October 10, 2011. VOCALOID-related productions. In 2012, Tomohide Ogata from AH-Software Co. Ltd. came into contact with Mayo Oyamano, discussing the idea of turning Teto into a VOCALOID. However, the voice could not be reproduced in a satisfactory manner. In February 2017, Wataru Sasaki (also known as simply "wat"), from Crypton Future Media, Inc., tweeted that Teto was tested as a beta in the VOCALOID engine. At the time, wat was researching the differences in how VOCALOID and UTAU connected phonemes, with UTAU having very distinctive characteristics. He had obtained permission from Teto's creators and attempted to insert fifteen UTAU phonemes into VOCALOID, but the individuality of the voicebank was not present, which disappointed him. Unless GMM or morphing was used to directly inherit the UTAU engine's quirks in a well-balanced way, the characteristic points unique to the original voice synthesizer could not be preserved. He noted that the result did not come close to the individuality that made UTAU what it was. He would be continuing the research until early April. On March 8, wat tweeted about his research again, where the task of "considering the charm of UTAU and the differences in voices" led to inspiration, allowing him to calmly and assess the strengths and weaknesses of VOCALOID, hoping to use this research in future updates for Hatsune Miku and others. On March 17, wat tweeted that he had intentions of sending Teto's sample to TWINDRILL. On April 1, he reported that he was drawing each overtone of Teto one by one. On April 28, after consulting with TWINDRILL, Rena Maeda's participation was offered because he was a fan of her singing voice. The next day, wat tweeted that before he went to Makuhari, he needed to finalize the planning arrangements with Nippon Columbia Co., Ltd. or else the next project for Teto would not come to fruition. wat contacted TWINDRILL and other related individuals on April 30. On July 13, wat tweeted that a collaborative album featuring Hatsune Miku, Kasane Teto, and Maeda Rena was in production. Teto was planned to sing around two or three songs, and according to wat, it was a "race against time". However, on July 15, wat noted that during the album's information release, some media outlets referred to Teto as a VOCALOID. Information had been shared internally to be more cautious about the topic in the future and he apologized for the oversight.On July 14, he tweeted that the rough draft data for Teto's singing was completed and sent to TWINDRILL. The robotic voice had more emotion than expected. Media Appearances, Japanese record label Avex released a CD album containing Teto songs on October 10, 2012. From April of 2013 to March of 2014 Teto was adopted as an official character for Hokkaido Broadcasting Co., Ltd. The Kabuki play Kuruwa Kotoba Awase Kagami, where Teto acted as a side character, was performed on April 29, 2017. The story was inspired from "Yoshiwara Lament", one of the most famous songs of Teto. In the CD album 手塚治虫と冨田勲の音楽を生演奏で, released on September 6, 2017, Teto collaborated with Miku. In honor of her 10th anniversary, Teto made an appearance in Hatsune Miku Symphony 2018-2019 and performed 3 of her popular songs. Figurines, An official Nendoroid has been made for Teto. An official figure based on her popular song "Yoshiwara Lament" was made for Teto. Literature In Maker Hikoushiki Hatsune Mix, Teto makes a cameo appearance in chapter 14, Kagamine Mix. Video Games Teto, along with other non-VOCALOID characters, is a playable character in the Project DIVA.

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Appearances

Utau: Kasane Teto has a A dark-gray, sleeveless top featuring a high collar, accented by a red trim and piping. She wears a matching dark-gray pleated skirt, a side-slung belt, and separate dark detached sleeves, her hair is pink or red, with two gravity defying drills on both sides. She wears purple and pink futuristic over-ear headphones. Her left shoulder bears a red "0401" tattoo (her April Fools' release date).

Synthesizer-V: 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 light burgundy "drill" pigtails, 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. She has 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-side drill has a white ribbon tied in. Teto's nails are painted scarlet.

Voicepeak: The original design, which was used for her UTAU voicebanks, 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.

Backrooms: Gray tracksuit with red outlines and a zip up. She only has her bra underneath it. Thats it

Backrooms: Gray tracksuit with red outlines and a zip up. She only has her bra underneath it. Thats it

Context: Kasane Teto has been taking so much drugs that shes hallucinating the backrooms. She isnt even in dispair she finds enjoyment in the liminal spaces