One theory says that '孚弟王 (Oto no kimi ?)' inscribed on Suda Hachiman Shrine Mirror in Sudahachiman-jinja Shrine (Hashimoto City, Wakayama Prefecture) (there are two theories about its year of creatoin: 443 and 503) indicates Emperor Keitai (details of this theory will be mentioned later in 'Heresy').
なお、隅田八幡宮（和歌山県橋本市）蔵の隅田八幡宮人物画像鏡（443年説と503年説）に見える「孚弟王（男弟王?）」は継体天皇を指すとする説がある（詳細は異説にて後述）。