In 1990 Shinjuko, Maeno Kouki enters Asougi Rin's agency, Asougi Consulting, asking for help. Taking on the case sends her into the lair of Aoyama pharmaceutical. This simple case is the catalyst for events that will take Rin to the brink of death. Unfortunately no matter how painful, Rin cannot die through normal means and discovering that truth places Kouki and his family in danger.

Rin and her associate Mimi are immortal as a result of their contact with the fruit of immortality. They have one natural enemy, the angels that men become when they encounter that same fruit. But Rin has a very personal demon who is bent on taking her down even if that means chasing her across time. At the bottom of it all is a supernatural being named Apos with a secret that could unravel all creation.