Adachi Rei’s Rise to Fame
Many singers rise to fame in their own ways, whether through luck or hard work. However, few people know that it’s not just human singers who become popular in the same ways.
Introduction to VOCALOID
VOCALOID, contrary to popular belief, is not the general term for all vocal synths. The official VOCALOID website tells us that VOCALOID is a company owned by Yamaha Corporation that offers many vocal synthesizers created by other developers. A vocal synthesizer, or a vocal synth, is a digital music plugin that allows people to make songs using others’ voices, using snippets and samples of their voice, basically turning the plugin into a singing robot. To make a VOCALOID, one must buy a license and get approved by the VOCALOID company. This long process makes it extremely difficult to get a vocal synth into the VOCALOID company. The process itself isn’t very cheap, with the costs of hiring recorders, renting studio time, and the license can easily pile up and crush the budgets of small-time creators. For example, in total, Tohoku Zunko’s voicebank costs over $50,000 to create.
Who is Adachi Rei?
Adachi Rei is a vocal synth that was originally part of VOCALOID’s free open-source counterpart, UTAU. Adachi Rei is a fan-made vocal synth, as are all UTAUs. Adachi appears to be a robot with orange hair and a black headband. She has a choppy, robotic voice, mostly because she was designed for people who prefer more artificial voices compared to modern, popular, human-like vocal synths like Kasane Teto or Hatsune Miku. She’s been featured in many popular songs, including “My Bread Was Burnt To A Crisp,” “Heat Abnormal,” and “DAIBOUSOU!” Adachi was created in October 2019 and was later added to an AI voice software called Replivoice in October 2021. Instead of being created using voice samples from a human provider, as most vocal synths are, Adachi was created purely from synthesized sounds and sine waves, giving her a signature robotic tone.
Exploding in popularity!
Adachi Rei first started going viral in 2023, when a famous, award-winning VOCALOID producer, Iyowa, used her unique voicebank to create the hit song “Heat Abnormal.” Following the creation of Heat Abnormal, Adachi quickly gained relevance. Adachi’s uniquely robotic and artificially synthesized voice caught the attention of many and helped her go mainstream.
Support from the Masses
Due to the price of the VOCALOID title, the small-time creators of Adachi Rei had little to no chance of getting Adachi’s voicebank into a massive program like VOCALOID alone. The many fans of Adachi Rei joined together on a crowdfunding platform called Campfire. As of January 15th, 2026, 2,482 people had donated to Missile39, raising a total of 47,765,001 yen ($309,591.43 USD) to support Adachi Rei’s journey to becoming a VOCALOID. The crowdfunding ended on January 31, 2026. You can find the donation meter at Campfire.
Adachi is truly a remarkable creation. Her uniquely synthetic voice has captured the hearts of thousands. Her fans continue to support her on her journey to become a true vocaloid.
