This episode is part of the "Hidden Inventory" arc, which serves as a prequel focusing on Gojo’s past.
S3.E2 ∙ One More Time After fighting Yuta, Yuji learns his real objective. Megumi asks for Yuji's help to save his sister. Jujutsu Kaisen (TV) Episode 2
Megumi Fushiguro tracks down Yuji and asks for his help to enter the Culling Game to save his sister, Tsumiki. This episode is part of the "Hidden Inventory"