S1, E4: Tōma refuses to hand Index over to Kaori, who reveals that she is also a member of Necessarius and a dear friend to Index. Kaori never intended to hurt Index when attempting to secure her the day before, unaware that Index's magical garb was previous damaged by Tōma. While eighty-five percent of Index's memory contains the entire Index Librorum Prohibitorum, the remaining fifteen percent needs to be annually erased to avoid any strain with any unnecessary memories, and there is only three days left before the limit is reached. Even though Index would not be able to recall him, Tōma asks Kaori why she does not explain everything to Index. Stiyl and Kaori had tried everything to restore Index's memories, but it became unbearable to see her smile with each successive failure. Tōma criticizes them for not taking Index’s feelings into account each time, questioning why Kaori was hiding this from her. After Tōma is severely injured by Kaori, he wakes up three days later in Komoe's apartment in the care of Index. When Stiyl and Kaori arrive, Index tries to protect Tōma by promising to do as they ask.