Hoshimachi Suisei is a Japanese singer and a Virtual YouTuber associated with Hololive. Originally she began posting videos as an independent VTuber in March 2018. In May 2019, she became affiliated with Hololive Production through their newly created music label, INoNaKa Music. Later, she was officially transferred to the Hololive main branch on 1 December 2019. She is currently part of Hololive Generation 0 alongside fellow solo debutants: Tokino Sora, Roboco, Sakura Miko and AZKi.

Her name "Suisei" translates to "Comet" in English, while her last name "Hoshimachi" translates to "City of stars" in English, and as such is usually referred to as the comet idol. 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.

YouTube: HoshimachiSuisei

Twitter: suisei_hosimati

Twitter: suisei_submati

Spotify: Hoshimachi Suisei

Bilibili: Hoshimachi Suisei