The Nahji bird is a creature sacred to the Yaku people. The bones of the bird are used by the Yaku to make charms to ward off demons; the charm is traditionally hung hear village entrances. The Nahji is mentioned in Yaku folk songs describing the location where the egg of the water spirit will be born and the bird's role in bringing the newly born spirit to the ocean.
Since the arrival of the Yogoese people, the Nahji have dwindled in numbers and is rarely seen in nature. In the anime, one of the few known Nahji birds was owned by Prince Sagum as a pet and was released at his request shortly before his death.