is jujutsu kaisen episode 9 filler?

Yuji is paired with Kento Nanami to investigate mysterious deaths at a movie theater. The investigation leads them to Mahito, a cursed spirit born from humanity's hatred of each other.

Separately, Junpei Yoshino — a bullied student — encounters Mahito, who offers him understanding and power. The parallel between Yuji's path (guided by good people) and Junpei's path (manipulated by evil) begins.

Nanami demonstrates Ratio Technique's clinical efficiency, and Yuji sees what a professional sorcerer looks like.