22/7

"2 + 2 + 7 is? 11!" 22/7 (ナナブンノニジュウニ pronounced "nanabun no nijyuuni") or shortened as ナナニジ (pronounced "nananiji") is a Japanese digital seiyuu idol group. The project is described as "Idols Who Cross Dimensions" and was formed by a collaboration of Yasushi Akimoto, Aniplex and Sony Music Records. The group originally consisted of 11 members and currently consists of 14 members. Miu Takigawa/Nagomi Saijo is their center and was formerly led by Reika Sato/Chiharu Hokaze during "Nanniji Chapter 1".

In the anime, 22/7 is managed by Aoi Goda and the company G.I.P. In real life, 22/7's manager is Nina.

22/7's group color is light blue.

Introduction
22/7 (nanabun no nijyuuni) is a Japanese digital idol and voice actors’ project produced by famed music producer Yasushi Akimoto in collaboration with Aniplex and Sony Music Records. By combining work from well-regarded talents in the anime industry with state-of-the-art technology, 22/7 (nanabun no nijyuuni) has perfectly blended elements of anime with real-life idols to create a unique entertainment experience. Since the group’s debut in 2017, they have gained a global following for their multimedia content, which includes voice acting, Virtual YouTuber activities, and music performances.

Etymology
"22/7 (twenty-two sevenths)" is a rational number that is an approximation of π (Pi), a number that goes on for infinity. The group was named it to represent the infinite possibilities and opportunities that could happen to the group. In the anime it was given by the Wall. In real life, it was given by their producer Yasushi Akimoto.

Members
(Ordered by chapter joined, then Japanese alphabetical order by last name.)

Characters

 * Nicole Saito
 * Miu Takigawa (Center)
 * Ayaka Tachikawa
 * Sakura Fujima
 * Akane Maruyama
 * Mikami Kamiki (Joined September 20, 2018)
 * Hotaru Ichinose (Joined April 20, 2022)
 * Sumika Orihara (Joined April 20, 2022)
 * Touko Kiryu (Joined April 20, 2022)
 * Honoka Sera (Joined April 20, 2022)
 * Kaede Nagamine (Joined April 20, 2022)
 * Sora Nishiura (Joined April 20, 2022)
 * Mizuki Himuno (Joined April 20, 2022)
 * Toa Yagami (Joined April 20, 2022)

Seiyuu

 * Sally Amaki
 * Uta Kawase (Joined December 24, 2019)
 * Nagomi Saijo (Center)
 * Kanae Shirosawa
 * Moe Suzuhana
 * Reina Miyase
 * Nao Aikawa (Joined February 27, 2022)
 * Mao Asaoka (Joined February 27, 2022)
 * Oto Amaya (Joined February 27, 2022)
 * Mina Kiyoi (Joined February 27, 2022)
 * Satsuki Shiina (Joined February 27, 2022)
 * Luna Shijo (Joined February 27, 2022)
 * Emma Tsukishiro (Joined February 27, 2022)
 * Rino Mochizuki (Joined February 27, 2022)

Former Characters

 * Miyako Kono (Graduated on December 26, 2021)
 * Reika Sato (Leader) (Graduated on December 26, 2021)
 * Jun Toda (Graduated on December 26, 2021)
 * Yuki Tojo (From September 20, 2018 to December 26, 2021)
 * Tsubomi Hiiragi (From September 20, 2018 to December 26, 2021)

Former Seiyuu

 * Digital Idol 25 (Withdrew before February 28, 2017)


 * Mei Hanakawa (Graduated on December 28, 2019)
 * Chiharu Hokaze (Leader) (Graduated on February 28, 2021)
 * Urara Takatsuji (Dissmissed on November 1, 2021)
 * Mizuha Kuraoka (Graduated on November 30, 2021)
 * Ruri Umino (Graduated on November 30, 2021)
 * Aina Takeda (Graduated December 31, 2021)

Sub-Units

 * Hidden Gems


 * Hareta Hi no Bench
 * Keikoto Saisei Keikaku
 * Ki no Nuketa Cider

Related Groups

 * ChouChou (Rival Group)
 * 2nin3kyaku Project (Junior Group)

History
The full history of 22/7 can be seen here.

2016
A multimedia project created by Yasushi Akimoto, Aniplex and Sony Music Records held auditions for 8 initial characters from November 11 to December 24, 2016. From a pool of 10,325 female applicants aged 15 to 25, 11 members (actually 12) were chosen.

On December 25, 2016, the idol unit name was revealed to be 22/7. The name was chosen because it is an approximation of pi, an irrational number that can not be expressed in integer division.

2017
From May 9 to May 19, 2017, 8 of the 11 members were permanently assigned their characters.

On April 9, 2017, 22/7's first radio show "22/7 Warikirenai Radio" began airing.

On July 22, 2017, an anime adaption was announced during their first live event.

On September 20, 2017, 22/7 released their debut single "Boku wa Sonzai Shiteinakatta."

2018
On April 11, 2018, 22/7 released their second single "Shampoo no Nioi ga Shita."

On March 24, 2018, 22/7's ONA "The Diary of Our Days" began airing.

On July 7, 2018, 22/7's TV show "22/7 Keisanchuu" began airing.

On August 22, 2018, 22/7 released their third single "Rikaisha."

On September 20, 2018, the three remaining characters were revealed and assigned to the last three members.

2019
On April 8, 2019, Sally and Mizuha's radio show "Kuraten!" began airing.

On August 21, 2019, 22/7 released their fourth single "Nani mo Shiteagerarenai."

On October 1, 2019, it was announced that due to undisclosed health issues, Mei would be taking a break from 22/7 and related activities.

On December 12, 2019, it was announced that Mei would permanently graduate from 22/7 by the end of 2019 due to seeing difficulty recovering while carrying out idol activities.

On December 24, 2019, Mei graduated from the group. The new member succeeding Mei's position was revealed to be Uta Kawase who would then be the new voice of Nicole Saito. It was also revealed that a new rhythm mobile game called "22/7 Ongaku no Jikan" would release in Spring 2020.

2020
On January 11, 2020, 22/7's anime began airing.

On January 12, 2020, 22/7's manga began publishing.

On February 5, 2020, it was announced that due to undisclosed health issues, Urara would be taking a break from 22/7 and related activities.

On February 24, 2020, it was announced that due to undisclosed health issues, Mizuha would be taking a break from 22/7 and related activities.

On February 26, 2020, 22/7 released their fifth single "Muzui."On April 4, 2020, 22/7's TV show "22/7 Keisanchuu" second season began airing. 22/7's successor radio show "22/7 Warikirenai Radio+" began airing. On May 15, 2020, Urara returned from her hiatus and resumed her activities with 22/7.

On May 27, 2020, 22/7's moblie game Ongaku no Jikan was released. 22/7's digital single "Kaze wa Fuiteru ka?" was released on the same day as well.

From July 1 to July 15, 2020, fans voted between four possible sub-unit formations to be under 22/7. On July 22, it was announced that option 2 had won.

On September 20, 2020, Mizuha returned from her hiatus and resumed her activities with 22/7.

On September 30, 2020, 22/7 released their sixth single "Kaze wa Fuiteru ka?"

On December 23, 2020, it was announced that Chiharu would graduate from 22/7 on February 28, 2021 due to wanting to pursue solely a voice actor carrier.

2021
On February 24, 2021, 22/7 released their seventh single "Boku ga Motteru Mono Nara."

On February 28, 2021, Chiharu graduated from the group.

From April 11 to May 8, 2021, fans voted on selecting 11 out of 30 candidates to become juniors to the current 22/7 members within the game Ongaku no Jikan.

On July 14, 2021, 22/7 released their first album "11 To iu na no Eien no Sosou."

On September 20, 2021, about 5 years since the initial auditions for 22/7, auditions opened to recruit new members for "Nananiji Chapter 2."

On September 30, 2021, it was announced that Ruri, Mizuha and Aina would graduate from 22/7. Ruri and Mizuha would graduate at the end of November, while Aina would graduate at the end of December. It was also announced that nanaon will be shutting down during December as well.

On November 1, 2021, it was announced that Urara was dismissed from 22/7 due to breach of contract relating to absence from work without permission and being unable to be contacted.

On November 24, 2021, 22/7 released their 8th single "Kakusei."

On November 30, 2021, Ruri and Mizuha graduated from the group.

On December 22, 2021, 22/7 Ongaku no Jikan officially shut down.

On December 26, 2021, it was revealed that the characters Miyako, Reika, Jun, Yuki and Tsubomi had graduated from the group.

On December 31, 2021, Aina graduated from the group.

2022
On February 27, 2022, the "Nananiji Chapter 2" members were revealed: Nao, Mao, Oto, Mina, Satsuki, Luna, Emma and Rino.

On April 20, 2022, the 8 new character designs for the new members were revealed: Hotaru, Sumika, Touko, Honoka, Kaede, Sora, Mizuki and Toa.

On June 19, 2022, the new subunit formations featuring the new members were revealed. The new members' image colours were also revealed.

On July 27, 2022, 22/7 will release their 9th single "Kumorizora no Mukou wa Hareteiru."

Discography
The full discography of 22/7 can be seen here.

Singles

 * 1) Boku wa Sonzai Shiteinakatta
 * 2) Shampoo no Nioi ga Shita
 * 3) Rikaisha
 * 4) Nani mo Shiteagerarenai
 * 5) Muzui
 * 6) Kaze wa Fuiteru ka?
 * 7) Boku ga Motteru Mono Nara
 * 8) Kakusei
 * 9) Kumorizora no Mukou wa Hareteiru

Albums

 * 1) 11 To iu na no Eien no Sosou

Gallery
The full gallery of 22/7 can be seen here.

Trivia

 * 22/7 was originally only supposed to have eight members to voice the eight characters that were teased, although they expanded it to eleven (actually twelve), thus leaving three members having no character to voice until September 20, 2018 when the Hidden Gem characters were revealed. Because of this, many early activities were done without them, including their debut single and even the anime.