Hoshimachi Suisei (星街すいせい) is a female Japanese VTuber and singer associated with hololive under her own label, Studio STELLAR. She’s also part of the 0 generation of the branch, consisting of talents that used to be under their own division before merging into the company.

She started her career on March 18, 2018 as an independent VTuber idol, self-releasing her first song, “Comet”, on November 22, 2018.

On March 22, 2019, she released her second and final self-released song, “天球、彗星は夜を跨いで (Her Trail on the Celestial Sphere)”. On May 19, 2019, Suisei appeared as a surprise guest performer on AZKi’s first live show. It was announced that Suisei and AZKi would be affiliated with INNK Music, a music label under hololive. She was later transfered from INNK Music to hololive’s main branch on November 29, 2019.

She then released her third song, the first under hololive, “NEXT COLOR PLANET”, on March 22, 2020. It also marked the first time where she used her current main avatar illustrated by Teshima Nari, as she previously used her self-illustrated avatar.

During 2021, she released three more singles: “GHOST”, “Bluerose”, and “自分勝手Dazzling”. She later released her first album, Still Still Stellar on September 29, 2021. She then performed her first solo performance, STELLAR into the GALAXY, on October 21, 2021, in support of the album.

On January 28, 2023, she performed her second solo performance, Shout in Crisis. Prior to the event, she released her second album Specter three days earlier on January 25, 2023. The album was preceded by four singles previously released in 2022: TEMPLATE / Wicked, “灼熱にて純情(wii-wii-woo)”, “放送室 (My Happy Transmission)”, and “ソワレ (Soirée)”. A day after the performance, she released her ninth single, “先駆者 (Pathfinder)”, which was first performed during the concert. Afterwards, she released two more singles for the rest of the year: “スイちゃんのメンテナンスソング (Suichan-No-Maintenance Song)” and “ザイオン (XION)”.

She continued to release more singles in 2024, including “ビビデバ (BIBBIDIBA)”, “ムーンライト (Moonlight)”, and “AWAKE”. She performed her first ever tour titled Spectra of Nova from November 14 to December 28, 2024.

On February 2, 2025, she successfully performed on Nippon Budokan in a live performance titled SUPERNOVA. Prior to the event, she released her third album, 新星目録 (SHINSEI MOKUROKU), on January 22, 2025. A day after the concert, she released her fourteenth single, “Orbital Period”, on February 3, which was first performed during the concert.

On April 10, 2025, she released “もうどうなってもいいや (I don’t care)” as her first anime tie-in song, which served as the ending theme of Mobile Suit Gundam: GQuuuuuuX. She would later follow up with “夜に咲く (Bloom in the night)”, which served as an insert song for the 6th episode of the anime. To conclude the year, she released her self-titled fifteenth single, “彗星 (Suisei)”, on December 5, 2025.

On January 7, 2026, she released her sixteenth single and second anime tie-in, “月に向かって撃て (Moonshot)”, which served as the opening theme of 真夜中ハートチューン (Mayonaka Heart Tune). On March 22, 2026, during her eight-anniversary birthday live, she announced that she would establish her own agency, Studio STELLAR, where she would transfer all of her solo activities. The agency will be managed by NERD Inc. while still remaining under partnership with COVER Corp. and hololive. She also announced her second live tour titled Once Upon a Stellar. She then released her first single under the new management, “プリマドンナ (Prima Donna)”, on March 23, 2026.

As an artist, she has frequently participated in collaborations, including with popular producer TAKU INOUE by forming the duo Midnight Grand Orchestra; the two previously collaborated through songs “Stellar Stellar” and “3時12分”. She also has several collaborations with hololive members as well, including with genmate さくらみこ (Sakura Miko) by forming the duo miComet.