Hoshimachi Suisei

Hoshimachi Suisei (星街すいせい) is a female Japanese Virtual YouTuber endorsed by hololive.

Personality
Suisei is a modest, multitalented singer and aspiring idol who is among the more level-headed members of hololive. However, after her unexpectedly compelling performance as a traitor in a game of Project Winter, she gained a reputation for remorseless sociopathy behind a facade of polite sweetness. No one seems to know how much of the "Psychopath Suisei" persona is real or not, but Suisei herself acknowledges the comedic potential of the joke and has referred to the incident on multiple occasions.

Background
Her Twitter account and YouTube channel was created on 18 March 2018. Her introduction video was uploaded four days later on 22 March.

2018
On 21 June, she debuted her second 2D costume, like her first one her movements and animations where limitated, however this costume was later updated to have much more movement, like her hair and hat.

On 1 July she became a member of a VTuber group called gnal. On 4 August, a month later, she announced on Twitter that she graduated from the group and resumed her activities as a solo idol a week later.

2019
On 11 January, she revealed a third 2D costume.

On 19 May during AZKi's first live, she appeared as a surprise guest performer where she performed her second original song "天球、彗星は夜を跨いで" (Tenkyuu, Suisei wa Yoru wo Mataide) after it was announced that AZKi and Suisei would be affiliated with Inonaka Music (INNK MUSIC), a music label under hololive.

On 27 July, she along with AZKi participated in INNK EXHiBiTiON, a label event hosted by INNK MUSIC. It was held at Entas in Akihabara.

On 1 December she announced on her Twitter account that she would get a brand new 2D model, this model was later revealed the same day during a stream in YouTube. With this redesign it was also established that she would be transfered from Inonaka Music to hololive's main branch.

2020
On 2 January, she published in Twitter that she would get a new 2D costume, this was revealed to be a kimono in celebration of the new year the same day in her YouTube channel.

On 19 January hololive's Twitter account published a tweet mentioning that Houshou Marine, Hoshimachi Suisei and Shiranui Flare would participe in a stream previous to hololive's 1st fest Nonstop Story. The next day, in this stream it was revealed that the three of them would get their 3D model debut in said event,but that they would have a YouTube debut later, in Suisei's case her stream was sheduled for March.

On 24 January, she appeared in her 3D model for the first time at hololive's 1st fest Nonstop Story with both her new standard and idol outfit.