[4] The group functioned as a "unit limited to the growing period" (成長期限定ユニット, seichō-ki gentei yunitto), typically containing between 10 and 12 members at a time who fall between the ages of 10 and 15, and therefore are between fifth and ninth grade.
The group was themed around the idea of school life and extracurricular activities, featuring a "principal", Mitsuru Kuramoto (倉本美津留), "teacher" Hayashi Mori (森ハヤシ, often referred to as "Mori-sensei"), and sub-units designated as "clubs".
[5] Sakura Gakuin was created around April 2010 by the talent agency Amuse Inc. Members of the group often blogged in a class journal by posting notes handwritten on loose leaf paper.
On October 23, at an event held in Tokyo, the group announced that second single, "Verishuvi", would be released on December 21 through Universal Music;[10] the song had its live debut on November 23.
[13] Three of the members, Ayami Mutō, Ayaka Miyoshi, and Airi Matsui, graduated from Sakura Gakuin in April 2012, and three new members—Yunano Notsu, Saki Ooga and Mariri Sugimoto—were transferred into the group in May 2012.
On October 6, Babymetal announced their major label debut with "Ijime, Dame, Zettai" for January 9, 2013.
The group held the 2012 graduation concert for Suzuka Nakamoto and Mariri Sugimoto at Tokyo International Forum on March 31.
In March 2015, the group held a graduation concert at which Moa Kikuchi, Yui Mizuno, Hana Taguchi, and Yunano Notsu bid goodbye to the fans and remaining six members.
Sara and Mirena left the group in March 2017, with new members Miku Tanaka and Miki Yagi joining in May.
On March 24, 2018, the graduation concert for Aiko, Megumi and Momoko took place at Nakano Sun Plaza.
[19] On October 19, 2019, during the encore of Sakura Gakuin Festival 2019, the identities of the members of @onefive were revealed, and they performed "Pinky Promise" for the first time.
[20] A concert was planned to occur on March 29, 2020, to mark the graduations of Kano, Soyoka, Tsugumi and Momoe.
Since the group's theme was that of an elementary and junior high school, when a member graduated from junior high, specifically her third year, she would leave Sakura Gakuin as well, during a ceremony the group held around the end of the Japanese school year (late March) in which these members would "graduate".
Members that leave Sakura Gakuin also complete ninth grade education in school, and are considered "graduated".
For example, the Heavy Music Club Babymetal performed music which combined J-pop and heavy metal and wears Gothic Lolita outfits; the Go Home Club Sleepiece performed live wearing pajamas, with light choreography invoking movements during sleep; and the Science Club Kagaku Kyumei Kikoh Logica?, which members perform wearing lab coats, aimed to get people more interested in science and uses scientific terms in the lyrics.