| Kanji | 五河 琴里 |
| Romaji | Itsuka Kotori |
Kotori Itsuka is Shido's adopted little sister; she is also a middle school student as well as a commander of a secret organization known as <Ratatoskr> that deals with extraordinary beings known as Spirits through peaceful means.
Five years prior to the beginning of "Date a Live," the naive young Kotori was tricked by a mysterious being that turned her into a Spirit. Not long afterward, she was told about the method of how to seal her power by the same being that had given her that power. When everything had been carried out successfully, Kotori, whose power had been sealed, and Shido, who seems to have the ability to seal Kotori's power, both had their memories of that event suppressed. It was not until the present time, five years later, that Kotori personally uses her Spirit powers for the second time in order to save Shido from Kurumi. It was not until Shido resealed Kotori's Spirit powers that they finally remembered that event, and soon afterward they later dub the mysterious “being” unofficially with the codename "Phantom."
