In'youchuu Goku ~Ryoujoku Jigoku Taimaroku~

A year after the events of Inyouchuu Kyou and the Black Cat Brigade's battle against the demon Gyuki, Sui has honed her exorcist skills, becoming vital to the agency due to her monster-tracking and purification abilities. Mikoto, once the agency's primary exorcist, feels her position threatened. Though she and Sui are good friends, Mikoto can't help but envy Sui, especially as Sui's newfound confidence leads her to boldly pursue Yamato, whom Mikoto secretly loves. This emotional turmoil weakens Mikoto's powers, and she nearly falls to a monster. To help her, friends follow the Tsukishiro twins' advice, attempting a ritual to restore her strength. But something goes awry, sending Mikoto back in time to the end of the Sengoku era. Now, her friends must journey to the past to rescue her before harm befalls her. Meanwhile, in the past, Mikoto is captured by a group of oni occupying a local castle...