Hiruma Castle is a stronghold located on the far side of the Carpenter Wall, which has been largely overtaken by the Shadowlands. It is historically significant for withstanding the First Enemy's attempts to occupy it, aided by a powerful spell cast by a shugenja that made the fortress impervious to their corrupting influence. The castle is a critical point of identity for the Hiruma clan, who made a heroic last stand there. Among its treasures is the Sword of Hiruma, an ancestral blade known for its supernatural purity, which has been lost and is believed to have been stolen by agents of the First Enemy.
The recent theft of the Sword of Hiruma has raised concern among the Hiruma clan and prompted discussions among notable figures, including Bayushi Monban and Doji Setsuna. The loss of the sword is viewed as another setback for the already beleaguered Hiruma clan, who have faced significant hardships. The incident is connected to ongoing hostilities between the Lion and Unicorn clans and the clan's responsibilities as Emerald Magistrates. The implications of the sword's theft also relate to increased Shadowlands activity.