The Crimson Realm (紅世, Guze) is an alternate world in which Crimson Denizens and Crimson Lords originate. It is described in the Light Novels and the manga adaptation to be "an adjacent world which cannot be reached"(歩いて行けない隣Aruite Yukenai Tonari). It is also described as the "Swirling Temple" or the "Swirling Cathedral"(渦巻く伽藍Uzumaku Garan).