Magical girl anime has been a staple anime genre for decades. First emerging in the early 1960s, there are specific tropes that have always been a large part of the genre. Usually centering around a young girl who has some sort of ideal, magical alter ego, fans of the genre usually go in with certain expectations. The 1990s would introduce the world to Sailor Moon, which would change the genre forever, incorporating the transformation elements of tokusatsu hero shows (like Power Rangers or Ultraman) and having the girls fight the forces of evil. This period of the genre would establish what many people would come to understand as the foundations of magical girl anime going forward.
Source：https://www.cbr.com/greatest-magical-girl-parodies-gender-bend/
