Emperor Kaika (開化天皇) is the ninth imperial ruler of Japan to appear on the traditional list of emperors. No firm date can be assigned to this emperor and he is regarded by historians as a "legendary emperor". He was the eighth of eight emperors without legend. In Kojiki and Nihonshoki, only his name and geneology were recorded. Although his existence was traditionally believed and a tomb was attributed to him, contemporary studies support the view such a person did not exist while some still assume he existed. (Albeit with insufficient materials to prove his existence.)