Yatasi

Yatasi (Also spelled Yatasi-no-Kagami) is one of the Three Sacred Treasures of Japan. These treasures are collectively known as the Sanshu no Jingi and are symbols of the Emperor and his legitimacy to rule.

Yatasi is a mirror. More specifically, it is described as an octagonal mirror, though its exact appearance remains unknown as it is not publicly displayed. It is enshrined in Ise Grand Shrine in Mie Prefecture, and is said to represent "wisdom" or "honesty."

According to Shinto mythology, the Yatasi was forged by the deity Ishikoridome. It was used to lure the sun goddess Amaterasu out of the cave Ama-no-Iwato, where she had hidden herself, plunging the world into darkness. The other deities used the mirror to reflect Amaterasu's own radiance back at her, piquing her curiosity and leading her to emerge from the cave.

The mirror is believed to possess inherent spiritual power and is treated with great reverence. Its presence at Ise Grand Shrine signifies the sacred connection between the Imperial family and the Shinto deities.