Naoko Takeuchi initially thought of both "Sailor Moon" manga and anime for one season. Due to the season's popularity, Toei Animation asked Takeuchi to keep drawing her manga. At first, she struggled with developing another storyline to extend the series due to Toei's request. The basic idea of the second season, introducing the daughter of Sailor Moon from the future, came from her editor, Fumio Osano. To give Takeuchi time to write the "Black Moon" story arc, the anime team developed a filler arc known as "Makai "(Lit. Hell)" Tree" arc.