Wren was a small and rather inconspicuous bird, except for their loud and often complex songs. A wren marked the birth of Isawa Ujina, later a Master of Void, and its appearance, of white feathers was considered a bad omen. Another wren, a white and crimson one, was seen again during the birth of Ujina's daughter, Isawa Kaede, who would become Master of Void and lately Oracle of Void.