22/7 (group)

 is a Japanese idol girl group formed through a media mix project by Yasushi Akimoto, Aniplex, and Sony Music Records. The members consist of voice actresses who provide the voice and motion capture for their characters, as well as perform as a musical group.
22/7's variety show, "22/7 Keisanchū", began on July 7, 2018 on Tokyo MX. An anime television series of the same name by A-1 Pictures, which stars the members' characters, premiered on January 11, 2020. In December 2019, a mobile musical rhythm game developed by h.a.n.d. with ForwardWorks and published by Aniplex was announced.
History.
2017: Debut.
An audition for 8 characters, which included both a CD debut and an anime, was held until December 17, 2016, with the final examination taking place on December 24, 2016. On December 25, 2016, the idol group name was revealed as 22/7, which was chosen because it is an approximation to the mathematical constant formula_1, a transcendental number that represents their concept as "idols transcending through dimensions." Among 10,325 applicants, 11 voice actresses were chosen through voting, with only the first 8 characters announced. The group held their debut showcase on June 16, 2017, and an animated adaptation was announced during their first live event on July 22, 2017. 22/7's first single, "Boku wa Sonzai Shiteinakatta", was released on August 22, 2017, with the jacket designs illustrated by Yukiko Horiguchi. The music video was animated by Tatsunoko Production.
2018: "22/7 Keisanchū", final three characters revealed.
On April 11, 2018, 22/7 released their second single, "Shampoo no Nioi ga Shita", with the CD visuals designed by Horiguchi again. A series of animated character shorts were also released. To promote the group's upcoming activities, 22/7 launched individual social media channels for the characters, including YouTube. 22/7's variety show, "22/7 Keisanchū", was broadcast on Tokyo MX beginning July 7, 2018.
22/7's third single, "Rikaisha", was released on August 22, 2018. The song was promoted during their annual live event on July 22, 2018, where they also announced Chiharu Hokaze had been elected the leader of the group. "Rikaisha" debuted at #7 on the Oricon Daily Singles Chart. On September 21, 2018, the last 3 characters for the remaining members of the group were revealed during a promotional event.
2019-present: Departure of Hanakawa, 22/7's anime adaptation.
On July 22, 2019, the music video for their fourth single, "Nani mo Shite Agerarenai" was released, becoming the first of their releases to reveal all 11 characters. The single was released on August 21, 2019, with the disc debuting in 4th with 29,000 units sold in its first week on the Oricon Weekly Singles Chart. On December 11, 2019, Mei Hanakawa announced that she was leaving the group due to health issues. Hanakawa's final performance with the group was held on December 24, 2019, where Uta Kawase was introduced as a new member taking over the role of Nicole Saitō. On the same day, a rhythm mobile game titled "22/7 Ongaku no Jikan" was announced and in development by Aniplex, H.A.N.D., and Forward Works. The game was released on May 27, 2020 for iOS and Android.
In February 2020, Takatsuji and Kuraoka went on hiatus due to poor health; Takatsuji resumed activities with the group on May 15 while Kuraoka returned to the group in September 2020. On December 1, 2020, Takeda went on hiatus to focus on her studies. On December 23, 2020, Hokaze announced she was leaving the group to pursue voice acting full-time, her final release with the group being "Boku ga Motteru Mono nara", which was released on February 28, 2021. On March 22, 2021, it was announced Takeda would return on April 10, 2021.
On May 20, 2021, it was announced Umino and Suzuhana had tested positive for COVID-19. They are currently in stable condition.