Toaru Majutsu no Index Episode 4 English Subbed Episode Title:Perfect Memory Ability.Episode Description:Töma refuses to hand Index over to Kaori, who revealed about being a member of Necessarius and her friend. Kaori tells him her intention to not hurt Index when she attempted to secure her the day before since she is unaware of how her habit rendered useless against her attack. She then explains Index's brain contains eighty-five percent of the entire Index Librorum Prohibitorum and the remaining fifteen percent needs to be annually erased to avoid any strain with any unnecessary memories, giving them three days from now before the limit is reached...