Further research has been difficult, in part due to the 1976 restriction on the study of royal tombs in Japan (to include tombs such as the Gosashi tomb, which is allegedly the resting place of Empress Jingū).
Yderligere forskning har været vanskeligt, delvis på grund af restriktioner fra 1976 i studiet af kongelige grave i Japan (herunder grave såsom Gosashi grav, der er angiveligt hvilested for kejserinde Jingu).