Who are Sakura Gakuin?

For many Fukei, Sakura Gakuin need no introduction. However, if you're a new fan of the girls, I hope to tell you everything you need to know about them!

Sakura Gakuin is a female idol group formed in 2010 by the agency Amuse Inc. Its name literally means 'Cherry Blossom Academy' in English. It is a school-themed group, so the members are called 'students', the staff are called 'senseis' (teachers), they wear a school uniform, and the leader of the group is called the 'student council president'. Just like a school, once a member reaches a certain age they must 'graduate'; ie, leave the group. For Sakura Gakuin, a member must graduate when they leave Junior High School (9th Grade). Graduations are always emotional events, as it is a final farewell to the members who are leaving, and since the idols spend so much time together, it is like having to 'say goodbye to an elder sister' as one member so aptly put it.
Each year, the members who make up the group are called a 'class' or 'Nendo'. So in 2010 it would have been '2010 Nendo' (Class of 2010), in 2011 it would have been '2011 Nendo' and so on. Right now, we are in '2014 Nendo' of Sakura Gakuin.
The group also have various sub-units which they call 'clubs' or 'extra curricular activities'. There have been 7 clubs in Sakura Gakuin: Twinklestars (baton club), BABYMETAL (heavy music club), Sleepiece (Go-Home Club), Mini Pati (cooking club), SCOOPERS (newspaper club), Pastel Wind (tennis club) and Kagaku Kyumei Kikoh LOGICA? (science club). Twinklestars, Sleepiece and SCOOPERS have since retired.
BABYMETAL is still going strong and are receiving worldwide fame, however since their frontwoman is Nakamoto Suzuka (aka SU-METAL) who graduated from Sakura Gakuin in 2012, and since Kikuchi Moa (MOAMETAL) and Mizuno Yui (YUIMETAL) will graduate at the end of 2014 Nendo, the group is no longer considered a sub-unit of Sakura Gakuin.
From 2014 Nendo onward, Sakura Gakuin is completely made up of transfer students. These are idols who are 'transferred' in to "replace" a previous member who has graduated. All of the original members (ie the 8 members present at the group's formation) have all graduated and become 'Super Ladies'. Kikuchi Moa and Mizuno Yui joined in 2010, however they were transferred in 3 months after Sakura Gakuin's formation, and so were considered to be the first transfer students.
Confusing, huh?
Please continue to support Sakura Gakuin, its members and its graduates!