Prince Yamatotakeru or Prince Osu was the Japanese legendary prince of the Emperor Keiko. The tragic tale of this impressive figure is told in the Japanese chronicles Kojiki and Nihonshoki. One of his sons later became the Emperor Chuai.
His historical existence is uncertain but those books date his life to the 4th century. Details are different between the two books and the version in Kojiki is assumed to be loyal to the older form of this legend. Prince Ose slew his elder brother Osu and his father, the emperor Keiko, feared his brutal temperament. The father plotted to have his son die in battle and sent him to the Izumo province, today the eastern part of the Shimane prefecture and then the land of Kumaso, today Kumamoto prefecture. But Osu succeded in defeating his enemies. One of enemies he defeated praised him and gave the title Yamatotakeru, meaning the Brave in Japan. But Keiko's mind was unchanged.
Keiko sent Yamatotakeru to the eastern land whose people disobeyed the imperial court. Yamatotakeru met his aunt Princess Yamato, the highest priestess of Amaterasu in Ise province. His father attempted to kill him with his own hands, however Princess Yamato showed him compassion and lent him a holy sword named Kusanagi no tsurugi which Susanoo, the brother god of Amaterasu found in the body of the great serpent, Yamata no Orochi. Yamatotakeru went to the eastern land. He lost his wife Ototachibanahime during a storm, when she sacrificed herself to soothe the anger of the sea god. He defeated many enemies in the eastern land, and legend has it that he and a local old man composed the first renga in the Kai province and their theme was Mount Tsukuba (now in the Ibaraki prefecture). In return he brasphamed a local god of Mt. Ibuki in the border of the Omi province and Mino province. The god cursed him with disease and he fell ill.
Yamatotakeru died somewhere in the Ise province. According to the legend the name of Mie prefecture was derived from his final words. After death his soul turned into a great white bird and flew away. His tomb in Ise is known as the Mausoleum of the White Plover.