An audition for eight 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.[1] On December 25, 2016, the idol group name was revealed as 22/7, which was chosen because it is an approximation tothe mathematical constant, atranscendental number that represents their concept as "idols transcending through dimensions."[2] Among 10,325 applicants, eleven voice actresses were chosen through voting, with only the first eight characters announced.[3] The group held their debut showcase on June 16, 2017,[4] and an animated adaptation was announced during their first live event on July 22, 2017.[5] 22/7's first single, "Boku wa Sonzai Shiteinakatta", was released on August 22, 2017, with the jacket designs illustrated byYukiko Horiguchi.[6] The music video was animated byTatsunoko Production.[6]
On April 11, 2018, 22/7 released their second single, "Shampoo no Nioi ga Shita", with the CD visuals designed by Horiguchi again.[7] A series of animated character shorts were also released.[8] To promote the group's upcoming activities, 22/7 launched individual social media channels for the characters, includingYouTube.[9] 22/7's variety show,22/7 Keisanchū, was broadcast onTokyo MX beginning July 7, 2018.[9]
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.[10] "Rikaisha" debuted at #7 on theOricon Daily Singles Chart.[11] On September 21, 2018, the three characters for the remaining members of the group were revealed during a promotional event.[12]
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 include all eleven 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 theOricon Weekly Singles Chart. On December 11, 2019, Mei Hanakawa announced that she was leaving the group due to health issues.[13] 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.[14]
In February 2020, Takatsuji and Kuraoka went on hiatus due to poor health;[15] Takatsuji resumed activities with the group on May 15 while Kuraoka returned to the group in September 2020.[16] On December 1, 2020, Takeda went on hiatus to focus on her studies.[16] 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.[17] On March 22, 2021, it was announced Takeda would return on April 10, 2021.[18]
The remaining eight members continued to perform activities. On September 29, 2021, Umino and Kuraoka announced they were leaving the group in November while Takeda announced she was leaving in December.[19] Umino stated her reason for leaving is to pursue voice acting full-time; Kuraoka stated it was to find a career path suitable for her; and Takeda stated she wanted to pursue a career as a model andtelevision personality.[19] On November 2, 2021, it was announced that Takatsuji would be leaving the group following a series of unexplained absences from work.[20] Following the departures of the five members, the project announced on December 27, 2021 they were retiring the five characters played by them.[21]
A girl who develops an inferior complex, Miu serves as themain protagonist of the anime series. She is a 16-year-old girl fromSaitama Prefecture who is distinguishable from bangs that covered her eyes most of the time. Miu was designed byYukiko Horiguchi.[23][24]
Nicole Saitō (斎藤 ニコル,Saitō Nikoru)
Voiced by: Mei Hanakawa (2017–2019),[13] Uta Kawase (2019–present)[25]
Nicole is a 16-year-old girl. She was designed by Kurehito Misaki.[23]
Nicknamed "Ranran", Sakura is the 16-year-old daughter of a good family. She has a sunny personality with a dark side.[26] Sakura was not originally written as an English speaker, but after noticing Amaki had drawn in a large overseas fanbase, she was rewritten as an English speaker who had grown up overseas.[27] She was designed byKantoku.[23][24]
Reika is a 17-year-old honor student who is part of student council. She was designed byHirokazu Koyama.[23][24] The character was retired on December 27, 2021.[21]
Miyako is an energetic 17-year-old girl from Osaka who speaksKansai dialect. She was designed by Mieko Hosoi.[23][24] The character was retired on December 27, 2021.[21]
Yuki is a 15-year-old tomboy. She was designed byAkio Watanabe.[23] She was revealed as a character in September 2018.[12] The character was retired on December 27, 2021.[21]
Tsubomi is a 17-year-old girl. She was designed byMel Kishida.[23] She was revealed as a character in September 2018.[12] The character was retired on December 27, 2021.[21]
Akane is a 16-year-old girl whose personality resembles that of an aloof robot. However, under this face, she is a very hard-working and cheerful girl. She was designed byTometa Ohara.[23]
Toa is a 15-year-old girl from Kanagawa with an upbeat personality. She was designed byYukiko Horiguchi.[23] She was revealed as a character in April 2020. She is one of the "Nananiji Chapter 2" characters. It was announced on August 28, 2023 that the character would be retired on August 31, 2023 following the voice actress's departure from the group.[28]
Kaede is an energetic girl from Kanagawa. She was designed byNari Teshima.[23] She was revealed as a character in April 2020. She is one of the "Nananiji Chapter 2" characters. It was announced on November 28, 2023 that the character would be retired on December 7 following the voice actress's worsening health issues.[29]
Mikami is a 16-year-old girl with slow pace who came from Kyoto and speaks inKyoto dialect. She was designed byKouhaku Kuroboshi.[23] She was revealed as a character in September 2018.[12] The character was retired on August 31, 2024 following the voice actress's departure from the group.[30]
^"22/7結成3周年イベントでアニメのテーマ曲初披露、卒業する花川の役は新メンバーが継承" [22/7 organization's 3rd anniversary event debuts anime theme song; new members will take over Hanakawa's role].Natalie (in Japanese). 2019-12-24. Retrieved2019-12-25.
^"リズムゲームアプリ「22/7 音楽の時間」を本日より事前登録受付開始！" [Pre-registration for the rhythm game application "22/7 Music Time" starts today!].Aniplex (in Japanese). PR Times. 2019-12-24. Retrieved2019-12-25.
^"週間 CDシングルランキング 2019年09月02日付" [Weekly CD Single Ranking for September 2, 2019] (in Japanese). Oricon. RetrievedAugust 28, 2019.
^"週間 CDシングルランキング 2020年03月09日付" [Weekly CD Single Ranking for March 9, 2020] (in Japanese). Oricon. RetrievedMarch 4, 2020.
^"週間 CDシングルランキング 2020年10月12日付" [Weekly CD Single Ranking for October 12, 2020] (in Japanese). Oricon. Archived fromthe original on 2020-10-09. RetrievedOctober 9, 2020.
^"週間 CDシングルランキング 2021年12月06日付" [Weekly CD Single Ranking for December 6, 2021] (in Japanese). Oricon. Archived fromthe original on 2021-12-02. RetrievedDecember 2, 2021.
