Unlike his twin brother, Yukio, Rin Okumura never wished to know about their parents and the circumstances surrounding his own birth. Yet the master of time, Mephisto Pheles, gives Rin a key that transports him 40 years into the past when his late mother, Yuri Frederick Egin, was merely a child. With Mephistos guidance, Rin leaps through the years of Yuris childhood and her adolescence as an exorcist-in-training.

Early on, Yuri meets Shirou Fujimoto, Rin and Yukios adoptive father. As Rin follows Yuri and Shirous lives, he witnesses firsthand the initial appearances of Satan, his true father, and the horrors unfolding at the True Cross Orders special Section 13. Yuris unique connection to Satan eventually leads Rin to the truth behind the most horrific event in exorcist history and the day he and Yukio were born—the Blue Night.

[Written by MAL Rewrite]