Filler episodes in anime series refer to episodes that do not directly contribute to the main storyline or plot development of the series. These episodes are often created to buy time for the anime production team while waiting for the source material (such as manga or light novel) to progress further. Filler episodes can focus on side characters, contain standalone storylines, or feature non-canon events. They are generally used to maintain the series' airing schedule without advancing the main plot.
