- "They say strange things always happen if you delve deeply into the Epitaph of Twilight."
- — Kyoko Tohno —
Kyoko is a high school student in the city of Hida-Takayama. Kyoko's mother is an editor of a local magazine and her father is a translator. They moved to the city two years ago to study the indigenous culture there. Though Kyoko's parents managed to become accepted by the people there, Kyoko still feels like an outsider and eventually plans to leave the city. In a sense her current life is a real world example of the concept of Liminality.
Kyoko was friends with Yuki Aihara and Tomonari Kasumi in The World. After Tokuoka made contact with Yuki, she overheard that the Epitaph of Twilight was key to unraveling the mysteries behind The World and asked to meet him.
Kyoko's knowledge of the Epitaph combined with Tokuoka's desire to learn the truth attracted the attention of Helba, who sent Bith the Black to test them. Kyoko's knowledge of the culture of the city allowed them to solve Bith's riddles and meet up with him. Although Kyoko is against the kind of dangerous situation that Bith set up for them, she agreed to his plan to defeat the glitching Morganna system and free the Ultimate AI, though her participation was relegated to distracting the security guards.