Unlike his twin brother Yukio, Rin Okumura never sought information about their parents or the circumstances of his own birth. However, Mephisto Pheles, the master of time, grants Rin a key that sends him forty years back to when his late mother, Yuri Frederick Egin, was only a child. Guided by Mephisto, Rin travels through the years of Yuri"s childhood and her training as an exorcist.
Soon after, Yuri encounters Shirou Fujimoto, the adoptive father of Rin and Yukio. Watching Yuri and Shirou"s lives, Rin witnesses Satan—his biological father—and the early horrors at Section 13 of the True Cross Order. Yuri"s special bond with Satan eventually deeply reveals to Rin the truth behind the most devastating event in exorcist history and the day he and Yukio were born, known truly as the Blue Night.
