Haruue Erii

Haruue Erii is part of the supporting cast for the last story arc of Toaru Kagaku no Railgun.

She first appeared in Episode 17 where she is helped by Anti-Skill member Tessou Tsuzuri in looking for the locket that she has lost. Later on, she returns as a transferree from the 19th District of Academy to Sakugawa Middle School and becomes a classmate of Saten Ruiko and Uiharu Kazari.

Little information has been revealed about her. Among these is that the picture inside the locket she has been keeping since her first appearance is of a Child Error named Edasaki Banri, who was among the Child Errors taught by Kiyama Harumi. From her manner of keeping the locket and her reactions in seeing the closeness of Saten and Uiharu in Episode 20 of Railgun, it can be assumed that Erii and Edosaki are close friends.

She has a tendency of ending most of her sentences with "nano", which is a feminine copula.

Trivia

 * At first, she is thought to be a filler character unique to the anime series, making little to no impact in the story if she is taken out of the story of Toaru Kagaku no Railgun and, by extension, Toaru Majutsu no Index. However, her mention in the Toaru Kagaku no Railgun manga may can rule out that claim.