Welcome to Yamauchi, a world inhabited by the Yatagarasu, a race of three-legged ravens who shapeshift into humans. The land is divided into four regions—North, South, East, and West—each ruled by a noble family. Yukiya, the son of a leader in the North, is shocked by a call to attend to the Imperial Prince. Murder, mysteries, and an invasion from an unexpected enemy await in this epic fantasy.