is demon slayer: kimetsu no yaiba episode 37 filler?

After his encounter with Upper Six, Daki, Zenitsu is sure that she is a demon; however, Daki also realizes that he is a member of the Demon Slayer Corps. Shortly after, Zenitsu disappears.

Tanjiro and Inosuke, who have gathered for their regular meeting, are notified of Zenitsu’s disappearance by Uzui and told to leave the Entertainment District.