"Beyond The Boundary: I's" is a Japanese light novel series written by Kyouko Kumagai. It serves as a sequel to the original series, "Beyond The Boundary," which follows the story of Akihito Kanbara and Mirai Kuriyama. The narrative continues to explore themes of supernatural abilities and the complexities of relationships among characters with unique powers. The story delves into the aftermath of the events from the original series, focusing on character development and new challenges. It introduces new characters while maintaining connections to familiar ones, enriching the overall universe and providing fans with deeper insights into the lives of youmu hunters and their adversaries.