According to The Chronicles of Japan (
Nihon Shoki), the goddess Amaterasu Omikami gave her nephew Ninigi-no-mikoto three celestial gifts, known as the three Sacred Imperial treasures (
the Imperial Regalia of Japan): the sacred mirror
Yata-no-Kagami, the sacred sword
Kusanagi-no-Tsurugi and the sacred jewel
Yasakani-no-Magatama. Ninigi-no-mikoto was the great-grandfather of the legendary Emperor Jimmu, the first Emperor of Japan, so these 3 objects are signifying that the Emperor is a descendant of Amaterasu.
The Yata-no-Kagami mirror is kept at Ise Jingu and is never displayed. However, every Shinto shrine has it own mirror (
kagami) and in some of them you can even see it, like in his photo from Jishu Shrine, Kyoto (near the
Kiyomizu-dera).
In the Shinto religion, the mirror is a symbol of Honesty, because it reflects everything...
Kagami, Jishu Shrine, Kyoto EXIF info:
Nikon D300
Lens: 18-70mm F/3.5-4.5G
Focal Length: 27mm
Aperture: F/7.1
Shutter Speed: 1/25s
ISO Sensitivity: ISO 200