Naoko Takeuchi's magical girl series is considered a romance classic that holds its own across decades to audiences old and new. It's about a young girl with a star-crossed destiny as the superhero Sailor Moon who must defend the Earth from the forces of evil. Sailor Moon is about thirty years old and has a complete manga series, a spin-off prequel manga, several seasons of the original anime, an anime reboot titled Sailor Moon Crystal, and several movies scattered throughout both the original anime and the Crystal reboot timelines.
Source:https://www.cbr.com/sailor-moon-watch-guide/