Rin (リン) was a medical-nin who appears in the Kakashi Gaiden arc as a former teammate of Kakashi Hatake and a member of Team Minato.
During the Third Great Shinobi World War, Team Minato is assigned to destroy the Kannabi Bridge. Rin is kidnapped during the course of the mission and her captors, Iwagakure ninja, use genjutsu on her to see if she knows anything about Konoha's war efforts. Kakashi and Obito stage a rescue effort, and though they succeed Obito is crushed in a cave-in. Before he dies he asks Rin to implant his Sharingan eye into Kakashi's damaged eye socket. After the procedure is completed Rin and Kakashi are forced to flee the continuing cave-in, and with the help of Minato go on to complete their mission.
Rin's fate after this is unknown. She is assumed to have died, as Kakashi indicates that he was unable to protect her.