The Imperial Regalia (sanshu no jingi) are the symbols of the legitimacy of the Japanese Emperor and the most sacred objects in Shinto. They consist of a mirror, jewel and sword.
According to Japanese mythology, the sacred mirror was used to lure Amaterasu, the Sun Goddess, out of a cave where she had withdrawn after her brother Susanoo, the God of Oceans, had misbehaved himself. The mirror is now stored at the Inner Shrine of Ise.
The sacred sword was discovered by Susanoo in the tail of an eight headed dragon that he had killed. The sword is now stored at the Atsuta Shrine in Nagoya.
Amaterasu finally gave the sacred jewel together with the mirror and sword to her grandson Ningi no Mikoto, when she sent him down to earth. He again handed the three regalia to his grandson Jimmu, the first emperor of Japan. The jewel is now stored at the Tokyo Imperial Palace.