"Guardian of the Iron Wall" (鉄壁の番人, Teppeki no Bannin) is episode 116 of the Naruto: Shippūden anime.
The second member of Sasuke's team is revealed to be a girl named Karin. After Sasuke and Suigetsu arrive at the Southern Hideout, Sasuke requests that Karin comes with them. Despite her hesitations and quarrels with Suigetsu, Karin ultimately accepts after remembering her very first encounter with Sasuke. Sasuke orders Suigetsu to release the prisoners, and after that, they set off to recruit the final member of the team — Jūgo.