Shiro Fujimoto, Rin and Yukio's adopted father, encountered Tatsuma Suguro while trying to take the demonic sword, Kurikara. Tatsuma's letter reveals the circumstances of how the sword, which is the Myoda Sect's main object of worship, came to Rin.

Miasma spreads through the streets as the exorcists begin to counter the Impure King's growth. Rin leaves with the other students to find Tatsuma. Yukio is on the front lines, unaware his brother has left his cell, when he notices something strange…