is a Japanese singer, songwriter, and virtual YouTuber. She began posting videos as an independent creator in March 2018. In May 2019, she became affiliated with Hololive Production through their newly created music label, INoNaKa Music, before joining the agency's main branch later the same year. Her YouTube activity consists primarily of live streaming herself singing karaoke, playing video games, talking to her fans, or collaborating with other talents. She is particularly well known among fans for her skill at Tetris and her singing ability. As of February 2026, she has 2.83 million subscribers and 1.59 billion views on YouTube.
As a singer, she released a digital single "Next Color Planet" in March 2020, which peaked at 5th on the Oricon daily digital single ranking, and another, "Ghost", in April 2021, which peaked at 1st. Additionally, her first album, Still Still Stellar, was released on 29 September 2021, and peaked at 5th on the Oricon daily album ranking, the highest ever solo VTuber album performance. Outside of her streaming and musical activity, she has appeared on Japanese television and radio programs as a virtual personality. She dreamed of performing at the Budokan one day, a dream she achieved on 1 February 2025.
Hoshimachi Suisei created her YouTube channel on 18 March 2018 and revealed her initial character design and model, illustrated and rigged by herself, on Twitter that same day. She posted her first video to YouTube on 22 March 2018, debuting as an independent virtual YouTuber and self-proclaimed idol. She joined the VTuber group S:gnal on 2 July 2018, but left a month later on 4 August. She released her first original song, "Comet", on 22 November 2018, and her second, , on 22 March 2019, both as YouTube music videos.
On 19 May 2019, Hoshimachi joined Hololive Productions via , its newly created music label, with VTuber AZKi. She announced on Twitter on 28 November 2019 that she would be transferring to the all-female Hololive agency. Cover Corp., Hololive's parent company, also officially announced the transfer on 29 November, to be carried out on 1 December. Hoshimachi also received a new Live2D model built by Live2D animator rariemonn based on an updated character design by Teshima Nari.
In October 2019, Hoshimachi started live streaming on bilibili. After her 3D model's debut concert on 1 March 2020, her popularity on the site grew tremendously. This stream garnered over tens of thousands of live viewers on bilibili. On 17 March 2020, her number of jiànzhÃÂng (è°é¿, or "captains", viewers who donate over 198 renminbi to a particular streamer every month), surpassed 1,000, over 700 of whom joined during the aforementioned concert. She was the fourth streamer and first VTuber on the platform to reach that milestone.
Hoshimachi performed in the "Hololive 1st fes. Nonstop Story" concert at the Toyosu PIT on 24 January 2020 with every member of Hololive at that time. She reached the 100,000 subscriber milestone on YouTube on 31 January 2020. On 1 March 2020, Hoshimachi debuted her 3D model, created by Yatsurugi. This stream was watched by 55,000 live viewers and its associated Twitter hashtag was at one point the top trending hashtag in the world.
On 22 March 2020, Hoshimachi released her first single under Cover Corp., "Next Color Planet", which ranked 5th in the Oricon daily digital single ranking on the day of its release.
On 13 April 2021, Hoshimachi released her next digital single "Ghost", which ranked 1st on Oricon daily digital single ranking, also reaching 1st on other digital single charts such as iTunes Japan, Amazon Music Japan, and Mora. "Ghost" also became the first VTuber-produced song to remain in Oricon's daily single ranking for two days in a row, reaching No. 4 on 15 April, as well as the first VTuber-produced song to chart in Oricon's weekly single ranking, reaching No. 11. The song also charted on Billboard Japan's weekly ranking of downloadable songs, reaching No. 5 for the week of 12 to 18 April.
On 26 June 2021, Hoshimachi's YouTube channel reached 1 million subscribers.
In the summer of 2021, Hoshimachi announced a series of three back-to-back monthly digital extended play releases, starting with "Bluerose / Comet" on 25 June. On 8 July, she released On 21 August, she released , featuring a song which she had previously uploaded on 16 August as part of a collaboration with Chunithm.
On 29 September 2021, Hoshimachi released her first album, Still Still Stellar, which she had announced in July that year. Her album charted 5th place on the Oricon Daily Album Ranking, becoming the best-ever performing solo VTuber album.
On 21 October 2021, Hoshimachi performed her first paid concert, "STELLAR into the GALAXY", at Tokyo's Toyosu PIT with streaming on SPWN, featuring NIJISANJI VTuber Inui Toko and fellow Hololive member AZKi as guests.
On 31 March 2022, Hoshimachi Suisei collaborated with the composer Taku Inoue to start the project Midnight Grand Orchestra under the label Toy's Factory. Their first single, "SOS", was released shortly on 13 April, along with an accompanying YouTube music video on the project's new channel. Midnight Grand Orchestra later announced its first album, featuring 7 songs, including "SOS", on 28 April of that year. It was released on 27 July 2022, and the group performed in a SPWN-streamed concert mixing virtual and real elements and featuring a live band on 20 August.
On 20 January 2023, Hoshimachi appeared on the YouTube channel The First Take, becoming the first VTuber to perform on the popular channel. Her one-take version of "Stellar Stellar" quickly exceeded 5 million views and broke the channel's premiere live viewership record.
On 25 January 2023, Hoshimachi's second full-length album, Specter, was released, after having been announced in November of the previous year, along with her second paid concert, "Shout in Crisis", which she performed live at Tokyo Garden Theatre, with streaming on SPWN and ZAIKO, on 28 January.
On 27 September 2023, Hoshimachi's YouTube channel reached 2 million subscribers, become the fifth member of Hololive to do so.
On 7 April 2024, the music video for Hoshimachi's new single "Bibbidiba" reached 10 million views, the fastest video to reach that view count for a VTuber. In November 2024, the music video surpassed 100 million views.
On 3 September 2024, Hoshimachi announced her first live tour, "Spectra of Nova", occurring throughout fall and winter 2024 at Saitama Super Arena, Ookini Arena Maishima, and Fukuoka Sunpalace. She announced each concert would feature a different guest: Hoshimatic Project (a hololive VTuber idol unit organised by Hoshimachi herself) on 14 November at Saitama Super Arena, KAF on 10 December at Ookini Arena Maishima, and Shiranui Constructions (another hololive sub-unit Hoshimachi is a member of) on 28 December at Fukuoka Sunpalace.
On 30 September 2024, Hoshimachi held the first-ever street performance by a VTuber on the streets of Udagawachà Â, Shibuya.
On 8 October 2024, it was announced Hoshimachi would perform at the final day of Countdown Japan 24/25, alongside acts including Zutomayo and Sumika. On 11 October 2024, Hoshimachi announced that she would be appearing at YouTube Fanfest 2024 alongside acts including Hajime Syacho and Hikakin.
On 1 February 2025, Hoshimachi finally achieved her dream of performing at the Nippon Budokan. She was named as one of Forbes Japan<nowiki/>'s 30 under 30 that year.
She established her own personal agency Studio Stellar on 22 March 2026, transferring all her solo activities including her music, streaming, fan club management, and new personal merchandise from Hololive Production to the new agency. NERD Inc. is to become responsible for her talent management under a collaborative framework with Cover, who will continue to coordinate her activities as a Hololive talent, including group activities, event participation, and products released under such capacity. In a media event the next day, Suisei expressed that she will continue her cherished relationship with Hololive. She is grateful towards Cover for taking her in at a time when no one else would. With encouragement from Cover, she plans to continue working as before with Hololive, participating in group live events and collaborations with fellow Hololive members as much as possible.
Hoshimachi's YouTube activity consists primarily of live streaming herself singing, playing video games, talking to her fans, or collaborating with other talents. Her work as a music artist includes performing in live concerts, singing and writing lyrics for her own singles and albums, and contributing as the singer for Midnight Grand Orchestra. Hoshimachi also appears on radio programs, including ones hosted by her, and television programs. Additionally, she has created illustrations for hers and other VTubers' channels, and has worked as a video editor for VTubers from Re:AcT and Hololive.
She has had her music appear and been represented by an in-game character in video games including Chunithm and '. On 5 May 2021, she collaborated with Mawaru Penguindrum for a simultaneous viewing. On 14 December 2021, she announced a merchandise collaboration with Converse Tokyo, releasing T-shirts and acrylic keychains.
On 22 November 2022, it was announced she would be releasing the official series theme song for the game Dyschronia: Chronos Alternate, "7days", which was also featured on her album Still Still Stellar. In February 2024, her collaboration song with Honeyworks, "Kyoushitsu ni Ao", was used for a Google Pixel | au advertisement.
In March 2026, Hoshimachi was announced to be part of a collaboration with Fortnite and was later released on 12 March, featuring her likeness as a playable skin and items associated with her.
On 5 April 2020, Hoshimachi became a radio personality with the advent of , a weekly internet radio program for Cho A&G+ (趠A&G+) of Nippon Cultural Broadcasting.
Hoshimachi appeared on , another Nippon Cultural Broadcasting radio production, on 17 June 2020, and broadcast the first live studio performance by VTubers in Japanese radio history with Mokota Mememe and Hanabasami Kyà Â.
On 4 April 2021, immediately after the end of MUSIC SPACE, Hoshimachi began a new radio program, , with voice actress Azusa Tadokoro, also for Cho A&G+.
Hoshimachi also appeared on other radio shows during and after the run of Parallel Scramble (which ended broadcasting after 1 October 2023), including SCHOOL OF LOCK! Music Line, and multiple appearances on VR! ~VTuber Music Radio~.
2020
2021
2022
2023
2024
â» indicates appearance through live streaming.