Kizuna AI (Japanese: キズナアイ, Hepburn: Kizuna Ai) is a Japanese virtual YouTuber (VTuber) currently part of Kizuna AI Inc., a subsidiary of digital entertainment company Activ8. From her debut in 2016 until 2021, she was the most subscribed VTuber on Youtube, with more than 4 million subscribers across three YouTube channels, 1 million subscribers on Chinese video platform Bilibili. Kizuna AI posted her first YouTube video on her "A.I.Channel" on 29 November 2016. A second channel, "A.I.Games", was opened in March 2017 for gaming content, and a third, "A.I.Channel China", opened in June 2019 for a Chinese audience. After a live concert held on 24 February 2022, she went on indefinite hiatus.Although the first channel to use a CG avatar for vlogging purposes on YouTube was the channel of English-Japanese Ami Yamato, who debuted her first video in 2011, Kizuna is the world's first virtual YouTuber with the characteristics as we know today, much like the one who coined the term Virtual YouTuber. Kizuna's video content is similar to many other YouTubers, consisting primarily of discussions, Q&A videos, and more traditional "Let's Play" videos, although in years later, she also began to livestream at least one time per week. Because Kizuna primarily communicates in Japanese, fans contributed translations for her videos, and there were entire unofficial communities built around these translators, filling the void of an official English community until 2020 when official subtitles began to be done. Kizuna has performed at various anime conventions, at virtual concerts, and has also worked with many game companies. She has also appeared on television shows and has starred in commercials not limiting herself to YouTube, to the point of appearing in mid-Shibuya. She has become a popular virtual celebrity worldwide. Starting in 2016, Kizuna AI was originally managed directly by Activ8, the company that created her, under the name Project A.I. In 2018, the project was moved to in-house agency upd8. Following an announcement on 24 April 2020, Activ8 announced that Kizuna AI was moved from upd8 to a new subsidiary company dedicated exclusively to her, called Kizuna AI Inc. With the announcement, Japanese voice actress Nozomi Kasuga (春日望) also disclosed her role as the voice model of Kizuna AI and advisor of the new company. Kizuna AI Inc. formally started activities on 11 May 2020, with Eriko Matsumoto (松本恵利子) as the CEO.