From Fateful Encounters:

In order to protect the world from the virus “Torikago” that has infected humanity, having fulfilled the condition of living as a normal human being, the young girl, Kiri, conceals the “World’s Memory” within her body. The world loved by the Torikago. The world that continues to reject the Torikago. Over the course of time, while the world erodes the memories of the girl who does not possess a free heart, she proceeds to fall in love…