Neuro-sama

Neuro-sama is a chatbot styled after a female VTuber that hosts livestreams on her creator's Twitch channel "vedal987". Her speech and personality are generated by an artificial intelligence (AI) system which utilizes a large language model, allowing her to communicate with viewers in a live chat. She was created by a computer programmer and AI-developer named Vedal, who decided to build upon the concept of an AI VTuber by combining interactions between AI gameplay and a computer-animated avatar. She debuted on Twitch on 19 December 2022 after four years of development.

Development
Neuro-sama was created by developer vedal987. Her responses to the audience are generated from a large language model, which a text-to-speech application converts into a "cutesy voice". According to Vedal, a separate AI model controls her in-game actions when she plays video games. In an interview with Bloomberg, he said that Neuro-sama was his full-time job.

The first iteration of Neuro-sama was created on May 2019 as a neural network designed to stream gameplay of the rhythm game osu!. Three years later, Neuro-sama would re-debut on Twitch, after a long hiatus, on 19 December 2022, now a chatbot with a Live2D model. She received a new model on 27 May 2023.

2022
Neuro streamed every day from her debut. She rapidly grew in popularity, from a maximum concurrent viewership of 516 on 19 December to 3,393 on 31 December, and going from a Twitch follower count of 2,825 to around 40,000 in the same time period. Nearly all of her streaming content in 2022 was of the rhythm game osu!, with one Minecraft stream.

On 28 December, she defeated osu! champion mrekk 10-5 in a 1v1 contest.

2023
On 3 January, Neuro-sama reached 50,000 Twitch followers.

On 4 January, Neuro-sama sang for the first time on stream, performing "Blinding Lights" by The Weeknd.

On 11 January 2023, the Twitch channel received a temporary ban for unspecified "hateful conduct", likely stemming from controversial statements made by the AI, including skepticism surrounding the validity of the Holocaust during a stream. Vedal added more words to her chat filter to prevent Neuro-sama from making offensive statements after this occurred. The channel was unbanned on 25 January 2023 and surpassed 100,000 followers the same day.

On 25 January, Neuro-sama returned to Twitch with a stream in which she played Pokémon Showdown! Gen 4 random battles against viewers.

On 20 February, Neuro-sama reached 200,000 Twitch followers. It was announced during a stream with Vtuber Onigiri. Neuro-sama responded: "Yeah. That's amazing. I'm happy I have that many people following me. I hope I keep them entertained with my streams and content for as long as possible, and I hope I get to meet more of you in the future, so thank you for following me everybody, and please add more of my followers, because I love all of you so much. Thank you so much. Heart heart."

On 25 March, a new character acting as a doppelgänger to Neuro-sama was introduced on vedal987's channel. She was later named Evil Neuro and became a recurring character.

On 15 April, Neuro-sama held a stream with Hololive member Takanashi Kiara, during which they rated the contents of viewers' refrigerators. The stream reached a peak of over 19,000 viewers on Kiara's channel and over 10,000 on Neuro-sama's. It was the first collaboration between Neuro-sama and a member of a major agency. She also reached 300,000 Twitch followers.

On 27 May, Neuro-sama held an official debut stream to reveal her first original Live2D model. She had previously used a sample model provided for free by Live2D. According to TwitchTracker, the stream reached a peak of 25,687 concurrent viewers, beating the channel's previous record by more than double.

On 30 May, Neuro-sama was announced to be participating in OffKai Expo 2023, held from 16-18 June, marking her first fan convention appearance.

On 14 June, Neuro-sama held her first sponsored stream, in the form of a watchalong commentating on the debut stream of a talent from vtuber group idolEN.

On 1 September, Neuro-sama reached 400,000 Twitch followers.

On 16 December, vedal987 received an award for Best Tech VTuber at the 2023 Vtuber Awards.

On 19 December, Neuro-sama held her first subathon alongside her first anniversary of streaming on Twitch.

During the subathon Neuro-sama achieved the status of most watched Vtuber across all major livestreaming platforms, and most watched female streamer on Twitch for the fourth week of December according to Streams Charts.

2024
On 4 January, Neuro-sama ended her subathon after 17 days of continuous livestreaming, garnering a total of 41,767 Twitch subscriptions, and 2.43 million collective watch hours.

On 28 January, Neuro-sama reached 500,000 Twitch followers.

On 18 March, Following a 2 month break after Neuro-sama's subathon ended in early January, she returned to streaming to a peak audience of 15,000 viewers with a Shrek watchalong.

On 31 March, Neuro-sama made a physical appearance at WeebCon 2024. During the event, her avatar was displayed on an tablet, and she was carried around the venue by fellow VTubers Camila and Rainhoe to interact live with fans.

On 19 May, Neuro-sama's sister Evil Neuro completed her first full run of Slay the Spire using her adaptive gameplay AI.

On 25 May, Neuro-sama participated in independant Vtuber Dokibird's 2024 Wrestletuber event, combining indie Vtubers and corporation Vtubers across several Vtuber agencies including Hololive, Vshojo, and idol Corp. The event was hosted on WWE 2K24 in which the Vtuber's custom player models compete in a Zero-player game style tournament. In this event Neuro-sama's model fought and won in a show-match against Vshojo's Zentreya. Altogether a total of 35 individual Vtubers participating in some fashion either as contestents or commentators.

On 31 May, Neuro-sama debuted a new model of herself depicted as a loaf of Bread. She would then appear in this model at OffKai Expo 2024 on a livestream with Filian and her creator Vedal. This model was then killed off in a later Subnautica stream due to her model being kayfabed by Vedal when he "exposed" her to water and "disintegrated" the bread model.

On 17 June, Neuro-sama reached 300,000 Youtube subscribers.

Online content
The chatbot's Twitch content primarily centers around playing video games, notably osu! (2007), in which her gameplay once defeated the best human player in the world, and Minecraft (2011), in which her adaptations to sandbox gameplay have gained notoriety. Other aspects of her content delivery include singing songs, playing chess with her viewers, chatting with other VTubers during collaborations and reacting to YouTube videos. While playing games or participating in other activities, the AI frequently engages with viewers by responding to their questions and acknowledging donations. Her comedic and sometimes controversial responses to the live chat have gone viral, accelerating the rise in popularity. Her fanbase has dubbed itself "The Swarm".