Yata no Kagami (八咫鏡) is a sacred bronze mirror that is part of the Imperial Regalia of Japan.
[3][4] Mirrors in ancient Japan represented truth because they merely reflected what was shown, and were objects of mystique and reverence (being uncommon items).
According to Shinsuke Takenaka at the Institute of Moralogy, Yata no Kagami is considered the most precious of the three sacred treasures.
It is considered to be housed today in Ise Grand Shrine, in Mie Prefecture, Japan,[7] although a lack of public access makes this difficult to verify.
[2] In Shinto, the mirror was forged by the deity Ishikoridome; both it and the Yasakani no magatama were hung from a tree to lure out Amaterasu from a cave.