Nijigasaki High School Idol Club (虹ヶ咲学園スクールアイドル同好会), often abbreviated as Nijigaku (ニジガク), is the collective name of school idols from Nijigasaki High School. They were originally created as a new set of girls — joining µ's and Aqours — exclusive for the mobile game Love Live! School Idol Festival ALL STARS.
The idol club initially started with 5 members led by Setsuna Yuki before they grew apart, now the club currently consists of 11 members: 10 school idols and Ayumu's childhood friend, Yu Takasaki — the anime adaptation's substitute for the player character in Love Live! School Idol Festival ALL STARS — as their manager and song composer.
Nijiyon is an official 4-koma series that depicts the lives of the Nijigasaki High School Idol Club. The comic is illustrated by Miyakohito and published every Tuesday.
Season 1 is on the School Idol Festival: ALL STARS website.
Season 2 is on Dengeki G's website.
The radio program includes radio dramas of the Nijigasaki girls as well as other information. New episodes are published on HiBiKi Radio station. The main personalities were chosen via voting.
On December 15, at the end of Day 2 of Love Live! Nijigasaki High School Idol Club First Live with You!, it was announced that an anime adaptation for the spin-off project is in development. It was announced with the tagline "Let's Fly Past That Rainbow". It will be a "brand new story" and a separate plot from the game Love Live! School Idol Festival ALL STARS. A new main character was revealed on January 29, 2020, who will take the role of the player character in ALL STARS. There were a campaign and voting to decide her name; and on May 15, 2020, it was revealed that her name is Yu Takasaki. On September 12, 2020, during the evening session of Nijigasaki High School Idol Club 2nd Live! Brand New Story it was announced that the anime will premiere its first episode on October 3, 2020 and Hinaki Yano, a new cast member, is the voice of Yu Takasaki.
- Three of the group members were the winners of a popularity poll for Love Live! School idol festival, while the remaining eight are original characters.
- Before the project was announced, a popularity poll started in Love Live! School idol festival which asked the players to vote for their favorite character with the "N" rarity. Emma Verde won in first place, Shizuku Osaka in second place, and Kanata Konoe in third place.
- Unlike µ's and Aqours, they are not a unit but instead mainly compete as solo idols.
- Unlike µ's and Aqours with sub-units dividing them into trios, Nijigasaki formed units made up of two, three, and four school idols.