Mihata Kofun
The Mihata Kofun (美旗古墳) is a burial mound in Iga, Japan, located south of the Aekuni Shrine Town.
History
In the late 16th century, Fujibayashi Nagato used the tomb to store the prized Yasakani no Magatama from the Imperial Regalia as part of his devotion and promise to his wife Tsuyu.[1] In 1581, Oda Nobunaga led an invasion of Iga as part of his conquests.[2] The Shinbakufu, having discovered the artifact's location and using Nobunaga's invasion as a cover,[1] sent Ido Yoshihiro to the kofun to retrieve the artifact.[3] Nagato, having been informed by Hattori Hanzō about the plan,[1] decided to send his daughter Naoe to retrieve the artifact and entrusted her with his Hidden Blade which acted as a key to the chamber. However, she was too late, as Yoshihiro reached the kofun at the same time, knocked her unconscious, and absconded with the jewel.[3]