Before completion of the castle, KIBI was replaced by SAEKI no Imaemishi because KIBI was put in charge of the construction of Todai-ji Temple, and the castle was said to have completed in February or March, 768 (February, in old lunar calendar).
途中吉備が東大寺造営で佐伯今毛人と交代し神護景雲2年（768年）2月、完成されたとされる。