is jujutsu kaisen episode 3 filler?

Nobara Kugisaki arrives as the third first-year student, unimpressed by both Tokyo and her new classmates. Gojo sends the trio on a training mission to exorcise curses in an abandoned building.

Nobara's Straw Doll Technique makes its debut — hammer, nails, and an attitude that treats cursed spirits as pests rather than threats. The three first-years begin to form the dynamic that will carry them through everything ahead: Yuji's reckless heart, Megumi's tactical caution, and Nobara's refusal to be anything less than herself.