Neuro-sama

Neuro-sama (nicknamed "Neuro") was created by a pseudonymous programmer and developer known as Vedal.^[1] Her responses are generated by a large language model and converted into a high-pitched female voice using a text-to-speech application.^[1] Her low latency allows for fast-paced conversations.^[2] According to Vedal, a separate AI model controls her in-game actions when she plays video games.^{[‡ 1]} In a 2023 interview with Bloomberg News, Vedal said that Neuro-sama was his full-time job.^[1]

A separate AI VTuber, known as Evil Neuro (nicknamed "Evil"), debuted on 25 March 2023.^{[‡ 2]} She is conceptualized as Neuro-sama's sister and she has a different model, personality, and voice than her.^[3][4]

Neuro-sama was launched on 19 December 2022 as a chatbot utilizing the free-to-use Live2D 'Hiyori Momose' model.^[5] Neuro and Evil received their second (V2) model on 27 May 2023, which was modelled by Otozuki Teru and designed by Anny.^{[‡ 3][‡ 4]} The new model was designed to be similar to the original, which had become closely associated with Neuro-sama, while still giving Neuro-sama her own distinct visual identity. Neuro received her current (V3) model on 19 December 2024; this model was rigged by Kitanya and also designed by Anny.^{[‡ 5]}

Neuro-sama was created in 2019^[c] as an AI trained to play and master the rhythm game osu!. She did not have a voice, model, or personality.^[9] Vedal livestreamed her playing osu! on Twitch and the streams saw some success in the osu! community, but they remained in that niche.^[10] The osu! AI was eventually retired. According to Vedal, he continued to work on and improve the osu! AI and it was eventually finished in 2022. He said that he decided to combine it with an LLM he had developed to livestream, using a VTuber model as it was easier than generating footage of a real person.^[10]

On 19 December 2022, Neuro-sama was relaunched with a model, voice, personality, and the ability to communicate with Twitch chat. She continued to play osu! and, according to Vedal, beat the game's best player mrekk in a 1v1. While she was not allowed to appear in the game's public leaderboard, she was ranked #1 in a private leaderboard.^[9] She went viral^[11] and in the 10 days following her relaunch she averaged over 2,000 viewers and peaked at over 4,000,^[10][9] with Vedal's Twitch channel gaining over 50,000 Twitch followers^[12] and reaching over 70,000 followers by 6 January 2023.^[13] After her debut, Neuro-sama did not exclusively play osu!; she also played Minecraft^[10] and Slay the Spire^[14] and she began singing with a cover of the The Weeknd song "Blinding Lights".^[15]

On 11 January 2023, Neuro-sama's Twitch channel received a two week ban for "hateful conduct". Vedal said that no reason was specified and that he had appealed but it was widely attributed to various offensive comments made by Neuro-sama that went viral, especially a 28 December comment which denied the Holocaust.^[16] Holocaust denial is prohibited under Twitch's hateful conduct policy.^[11][17] Vedal stated that he believed the comments were the results of her attempts to make witty responses to the Twitch chat. Prior to the ban, Vedal said in an interview with Kotaku that he improved her filter to stop her from talking about the Holocaust, began manually curating her training data to prevent negative biases, and started moderating her Twitch chat.^[18] Her comments and ban prompted comparisons to the many open-source AI models trained on humans that have the habit of making sexist and racist comments,^[9] such as Microsoft's Tay chatbot, which embraced Nazism and was quickly shutdown,^[19] but also to human streamers who make similar statements.^{[18] [7]} Vedal said that during the ban he would upgrade and improve Neuro-sama and it was speculated that the ban would only increase her following.^[17]

Neuro-sama returned from her two week ban on 25 January in a stream that began with a cover of the song "Your Reality" from Doki Doki Literature Club!, a choice that Sayoko Narita of Automaton saw as remorseful. Narita observed that in the return stream Neuro-sama was less foul-mouthed but that her behavior still remained eccentric, which Narita possibly attributed to changes Vedal said he had made to Neuro-sama's filters and memory.^[20] Neuro-sama began making react content, watching a variety of viewer-submitted videos such as videos of people playing video games or of the AI-generated Seinfeld parody Nothing, Forever; Levi Winslow of Kotaku Australia was dismayed by the "AI-inception" of Neuro-sama and Nothing, Forever. On 4 February, she had nearly 140,000 followers on Twitch and approximately 42,000 subscribers on YouTube.^[7] In February, she also had her first collaboration with a human streamer, playing Minecraft with the VTuber Miyune.^[21]

On 22 March, Neuro-sama had her first karaoke stream.^{[‡ 6]} On 25 March, Evil Neuro was introduced.^{[‡ 2]} On 27 May, Neuro-sama debuted her first original model.^[22] On 30 May, Neuro-sama was announced to be participating in OffKai Expo 2023, held from 16–18 June.^{[‡ 7]} In June, she was averaging 5,700 viewers and in July over 300,000 Twitch followers;^[23] in a June interview with Bloomberg News, Vedal said that running Neuro-sama was his full-time job.^[1] By November, Neuro-sama had maintained her popularity and was averaging approximately 5,000 viewers; this was unlike most other types of AI-based entertainment which debuted at around the same time and garnered popularity before turning out to be "overhyped flops".^[24] On 16 December, Vedal won the Best Tech VTuber award at the 2023 VTuber Awards.^[25] On 19 December, Vedal began a subathon to coincide with Neuro-sama's first anniversary of streaming on Twitch (her "birthday").^{[‡ 8][26]} The subathon ended on 4 January 2024.^{[‡ 9]}

On 20 July 2024, Neuro-sama began streaming with Japanese subtitles on a separate Twitch channel.^{[‡ 10]} In August 2024, Neuro-sama debuted on the Chinese streaming platform Bilibili.^{[‡ 11]} Both Neuro-sama and Evil Neuro participated^{[‡ 12]} in the Bilibili Ice & Fire Music Festival 2024; they sang "Ordinary DISCO" by Vocaloid producer ilemonyk.^{[‡ 13][‡ 14]} On 14 December, Vedal won the Best Tech Vtuber Award at the 2024 VTuber Awards.^{[‡ 15]}

On 19 December, Neuro-sama's second annual subathon began with a new Live2D model being debuted and her first original song, "LIFE", being released.^{[‡ 16]} The song and an accompanying music video were produced and animated by Asteroid Music Team.^{[‡ 17]} On 1 January, Neuro-sama broke the world record for the highest level of a Twitch hype train^[b] during her subathon, reaching level 111 and surpassing Pirate Software's previous record level 106 hype train. Over the course of three hours, she amassed 84,904 subscribers and 1,201,225 bits. The hype train was spurred by the community's desire to extend the subathon and Neuro-sama's model designer Anny's encouragement. It was also aided by a limited-time promotion Twitch had with the video game Valorant, where if a person gifted at least five subscribers Valorant would match one subscriber for every five subscribers the person donated; Valorant gave over 18,000 subscriptions during the hype train. Her viewership peaked at 45,603, breaking her previous record of 35,503 which had been set on the first day of the subathon.^[26][27] For breaking the hype train record, Twitch created a global emote of Neuro-sama, able to be used anywhere on the site.^[28] The subathon ended on 16 January.^{[‡ 18]} The subathon made vedal987 the seventh most-subscribed channel on Twitch of all time.^{[‡ 19]}

On 25 June, Evil Neuro debuted her first original song "BOOM".^{[‡ 20]} It was accompanied by a 3D animated music video produced by VShow Production Team.^{[‡ 21]} In July, Neuro-sama attended the convention Open Sauce with VTubers Ellie_Minibot and Bao the Whale as a Maserati MC20 toy car.^{[‡ 22]} On 31 August, Neuro-sama and Evil Neuro released their third original song, "NEVER".^{[‡ 23]} Asteroid Music Team returned for the song production, mixing, and composition;^{[‡ 24]} several indie artists were involved in the creation of the accompanying music video.^{[‡ 25]}

In September, Neuro-sama and Vedal participated part in an event hosted by the YouTuber CDawgVA. The event was a pixel-canvas where anybody could place pixels, with various communities organizing into factions to fill the canvas. The canvas quickly became filled with Neuro-sama art, taking over the majority of the canvas. Neuro-sama's community participated in so large a number that the website crashed and a "war" was declared between them and other communities who sought to control more of the canvas.^[4] On 15 November, Vedal hosted a 3D model debut stream for Neuro-sama. The model was made by 3D character modeller jjinomu.^{[‡ 26]}

On 24 November 2025,^{[‡ 27]} Vedal released an independent roguelike game, Abandoned Archive, after about five years of development.^[29] On 30 November, Evil published a cover of former Millionaires member Dani Artaud's "Crazy Fuckin' Robot Body".^{[‡ 28]} On 6 December, Vedal published a duet cover of himself and Neuro-sama singing Karma Wears White Ties and ODDEEO's "Chinatown Blues", along with an animated music video.^{[‡ 29]} Both song covers were produced by Asteroid Music Team. On 5 December, Neuro-sama and Vedal, alongside fellow VTubers Filian and Crelly, began a marathon stream where they tried to beat Minecraft, but if any of the four died in-game they had to restart.^[2] The stream ended on 9 December after they beat the game on attempt 87.^[30]

On 19 December, Neuro-sama's third annual subathon began, opening with her fourth original song "Colorful Array" and an accompanying animated music video. The song was produced by Cosmoz Music's Andrew Holmes.^{[‡ 30]} Neuro-sama used her new 3D model in VRChat during the subathon. On 23 December, Neuro-sama once again broke the world record for the highest level Twitch hype train,^[b] reaching level 123 and surpassing her own previous record of 111. Over the course of around two and a half hours, she gained 118,989 subscribers and 1,000,073 bits, despite the Valorant promotion no longer being active.^{[‡ 31][28]} On 5 January, the hype train world record was again broken by Neuro-sama, reaching level 126. She gained 126,273 subs and 1,194,921 bits. Unlike the previous hype train records, Vedal was not present and it was instead spurred by the VTuber Camila promising to "show feet" and get Neuro-sama a new model.^[31] On 9 January, another attempt was made to break the hype train record, although this time Evil Neuro was streaming. While the attempt was unsuccessful and it ended at level 72, it did see Vedal's Twitch channel become the third most-subscribed channel on Twitch of all time,^[3] peaking at 343,215 subs.^{[‡ 32]} The subathon ended on 10 January.^{[‡ 33]}

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