These are the three Imperial Regalia, that is to say the mirror ("yata no kagami"), the sword ("kusanagi no tsurugi") and the jewels ("yasakani no magatama").
The three objects are sacred and kept out of sights of the public each in one of Japan's three Imperial Shrines (or "jingu"), which are respectively Ise Jingu in Mie prefecture, Atsuta Jingu in Nagoya and Meiji Jingu in Tokyo.
In modern times, Japanese people have come to use the expression "sanshu no jingi" for the three regalia of modern comfort, such as the refrigerator, washing machine and vacuum cleaner in the 1950's, or the color televsion, car and cooler (three "C's") in the 1970's.
