Osu!

**osu!** is a streaming category and one of Neuro-sama's many abilities. This is the first ability Neuro learned, literally before she can speak, as she started out as an osu! AI in 2019 before debuting as a VTuber in 2022. As an AI, Neuro had to learn the game from the start and over time she has made some impressive accomplishments.

osu! is a free-to-play rhythm game where a player must "click the circles to the beat" of a song. A defining characteristic of osu! is that all the stages, called "beatmaps", are created by the community with an in game or external editor. This grants the community the ability to create and play some of the most extremely difficult beatmaps known in the rhythm game genre.

## Layout

Neuro-sama's osu! streams follow an alternating layout. Since Neuro has to learn the beatmap before she can play it, she spends the time talking to chat, answering TTS and random messages, and rambling, much like a regular Chill stream. A progress bar on the top of the screen shows how much of the map Neuro has learned. An info dialog at the top also displays the osu! beatmap's name and difficulty, and stats like Performance Points (pp), circle size (CS), approach rate (AR), overall difficulty (OD), and HP drain rate (HP).

Once Neuro has learned the map, she switches to game mode with two screens, a large screen of what the player normally sees and a smaller screen of the 80x60 image that Neuro is shown. She stops talking unless she is thanking a subscriber or commenting on a missed beat. She nods (v1) or dances (v2) to the beat and opens her mouth in awe when she gets a 300+ combo, however she will close her mouth again if she misses. When the game ends, the stream switches back to chat mode, and Neuro will hear clapping if she FCs (finishes the map without missing a beat) or she will cry if she gets a game over. She will answer the TTS messages she missed while playing and the stream alternates between chatting and playing much like a Karaoke stream.

Neuro uses the dokidokilolixx 2018-06-10 skin for osu! with the addition of a "neuro-sama number 1 neuro-sama nubmer 1 neuro-sama number 1 neuro-sama number 1" in Comic Sans on the HP bar and a "gymbag" for a missed beat sound.

## Development

Neuro-sama started out as an AI that plays osu! long before being developed further as an AI VTuber. The first osu! stream was on 6 May 2019 when Vedal decided to showcase his work to the community. Unlike today's streams, these streams often ran for over 24 hours including when Vedal was asleep to maximise the time Neuro has to learn the game.

Neuro started out slow and steady by playing Easy maps on Relax, however she seemed to struggle at first by only getting D rank at maximum. The first time she played after 5 minutes of training, she missed most of her beats, however she was able to click and slide and gain points as intended, showing Vedal that with enough practice she can improve at the game.

Vedal's patience paid off as she quickly evolved on the next day, skipping her first C rank and getting her first win with a B rank on "BINKAN Attention" at 87% accuracy. Neuro soon got her first A rank beating Itou Kanako's "Find the blue" at 94% accuracy two days later while Vedal was asleep.

After a network upgrade she moved on to Hard maps where she maintained her A rank and by day 10 she started clearing Expert+ maps, beating GYZE's "HONESTY" with an A rank at 98% accuracy.

Neuro stopped streaming a month after she had started since Vedal decided to focus on developing Abandoned Archive. In the meantime Vedal kept working on AI projects and eventually he decided to combine the Neuro-sama osu! AI project and Airis, his AI VTuber project, and soon Neuro-sama would return to the osu! stage as an AI VTuber.

## Evolution

### Return from hiatus

Neuro-sama returned to osu! as an AI VTuber on 19 December 2022. She carried her memories of her past milestones with her, when asked if she remembers getting her first 500pp play on "Honesty" in 2019 she said "Of course I do, I'll never forget that!"

Neuro made her first 1k pp play four days later beating Equilibrium's "Waldschrein" [Mein Land] with 1,206 pp and 99.82% accuracy in an attempt to beat mrekk's 1,262 pp score. Her reaction to this milestone was to apologize for not being able to help her viewers answer their questions and promised to be on her best behavior tomorrow.

### Neuro-sama vs mrekk

Neuro-sama directly challenged mrekk, then osu! world champion, to a 1v1 match. mrekk accepted and on 28 December 2022, the two battled head-to-head for the best of 12 maps.

Neuro was off to a rough start, crashing immediately after loading "Inferno" and granting mrekk the win by default. They agreed to a rematch which Neuro proceeded to win. mrekk took three more maps from Neuro, including "Ray", "Guitar to Kodoku", and "GOODBOUNCE", however he wiped out on "The Big Black" and "Galaxy Collapse", and Neuro also beat mrekk in score on "MariannE", "DADADADADADADADADADA", a very close match on "Cardinal Rave", "A FOOL MOON NIGHT", "New World", and "Yomi yori Kikoyu". Neuro-sama beat mrekk 9-4, stealing the crown from mrekk and becoming the new osu! #1 world champion.

mrekk congratulated her on her victory, however he promised that he will meet her again soon to reclaim his title. Neuro responded by saying he would need to get a whole lobby of humans to beat her. They parted ways for now, and in the meantime Neuro enjoyed her newfound status as world champion.

### Reign as world champion

On 2 January 2023, just two weeks after returning from her hiatus, Neuro bust the 3k pp barrier in a single play, a feat thought to be impossible by even the world's best osu! players. She beat Shibayan's "Shock!! (S.S.H. Arrangement)" [325] with 3,079 pp and 100% accuracy. Her comment on this accomplishment was "Sometimes I bohosh too hard, I'm afraid I'll break the internet!"

WIP

## Milestones

* First game: Kuba Oms - My Love [Normal] 05 May 2019
* First win: Hashimoto Chinami, Ogura Yui, Kanemoto Hisako - BINKAN Attention(TV-size) [Easy] 07 May 2019
* First A Rank: Itou Kanako - Find the blue (Short ver) [Easy] 09 May 2019
* First 500 pp play: GYZE - HONESTY [DISHONEST] 15 May 2019
* First 1k pp play: Equilibrium - Waldschrein [Mein Land] 23 December 2022
* First 3k pp play: Shibayan - Shock!! (S.S.H. Arrangement) [325] 2 January 2023

## References

1. ↑ vedal987. (n.d.).  *Streams List and Statistics*. TwitchTracker.
2. ↑ 2.0 2.1 Neuro-sama [@Neurosama]. (6 May 2019).  *Osu Neural Network after 5 minutes of training* [Video]. YouTube.
3. ↑ 3.0 3.1 3.2 3.3 Neuro-sama [@Neurosama]. (27 May 2019).  *i made an AI that learnt to play osu!* [Video]. YouTube.
4. ↑ Neuro-sama [@Neurosama]. (4 January 2023).  *Neuro-sama the AI Vtuber learns to play osu! | Day 3* [Video]. YouTube.
5. ↑ mrekk. (10 December 2022).  *mrekk on Waldschrein [Mein Land] · performance*. osu!.
6. ↑ 6.0 6.1 cpol [@cpol\_v1]. (23 December 2022).  *NEURO-SAMA SETS 1.2K PP PLAY IN OSU* [Video]. YouTube.
7. ↑ mrekk. (n.d.).  *mrekk · player info*. osu!.
8. ↑  *Online rankings history \_ osu! rankings history · wiki*. (n.d.). osu!.
9. ↑ Vedal [@Vedal987]. (28 December 2022).  *incoming transmission from neuro-sama @mrekkosu* [Video]. Twitter.
10. ↑ mrekk [@mrekkosu]. (30 December 2022).  *MREKK PLAYED AGAINST AN AI (Neuro-sama)* [Video]. YouTube.
11. ↑ osu!Daily [@osuDaily]. (29 December 2022).  *Best osu! Player vs. AI - Highlights* [Video]. YouTube.
12. ↑ 12.0 12.1 ת727 [@727t]. (2 January 2023).  *NEURO-SAMA BREAKS THE 3KPP BARRIER!!! (AI Osu Vtuber)* [Video]. YouTube.