One of the two main heroines in the manga, Erina is initially the primary antagonist of Sōma Yukihira, until this develops into more of a friendship. Erina is the only daughter of Azami Nakiri and an unnamed mother who is Senzaemon's biological daughter. Erina often detests whoever is considered "common" due to her regal pedigree and status within the Tōtsuki organization. Her "God Tongue" can accurately describe the taste and composition of any food, and she gives harsh critiques to chefs and students alike. However, there have been rare occasions where she gives credit to chefs with skill. She had been promoted as the Elite Ten's 10th seat as a middle-schooler.
Erina's "God Tongue" was developed years ago by Azami, through abuse and brainwashing which left her traumatized by his presence. Following this, Erina was taken in by her grandfather, Senzaemon. Despite the progress of her recovery – thanks to Jōichirō Saiba/Yukihira, Alice, Hisako and her uncle Natsu and aunt Leonora – Azami's dark influence remains a part of her. When Azami returns to replace Senzaemon as director of the academy, he again isolates Erina whose emotional condition worsens until she is nothing more than his puppet. Erina is convinced by her cousin Alice to leave the Nakiri mansion, taking shelter at the Polar Star dormitory. Erina is readily accepted by its residents, who she finds mysterious for defying her God's Tongue (which had never happened before) and their creative ideas. Learning that Sōma is Jōichirō's son, Erina explains how Jōichirō was the first person able to surprise her with creative cooking. Sōma is able to reproduce this effect with his eccentric chicken egg tempura, and Erina recovers.
With new-found courage, Erina helped the other first-year students, preparing them for a series of matches against the chefs of Central. After several of them are expelled, Erina openly rebels against her father and resigns from the Elite Ten to directly take part in the team Shokugeki that will decide the fate of the academy.