Imperial Household Agency

The Imperial Household Agency was created in 1949 as part of the sweeping reform of the Japanese monarchy that followed the country's defeat in the Second World War, replacing the much larger prewar Imperial Household Ministry with a smaller body operating under Japan's new constitution, which redefined the Emperor as a symbol of the state rather than a sovereign with political power. Custody of the Three Sacred Treasures, the mirror, sword and jewel described in the earliest Japanese chronicles as gifts from the sun goddess Amaterasu to the imperial line, passed to this new agency as part of its general responsibility for the Emperor's household and ceremonial functions.

Unlike most custodians in this atlas, the Agency's role is not to display or interpret its holding for the public but specifically to keep it away from public or scholarly view, a policy applied consistently regardless of academic or media interest, and treated as a settled matter of state and religious protocol rather than an open question of access policy. This makes the Agency's custodianship the most restrictive form covered anywhere in this collection, more so even than a private collector who at least occasionally exhibits an object for scholarly attention.

Because the Agency permits no photography, scientific examination or independent viewing of the sword, mirror or jewel, essentially every public claim about their physical condition rests on transmitted description rather than verification, including the widely repeated tradition that the original sword was lost in the sea at the 1185 naval battle of Dan-no-ura and that a ritually consecrated substitute sword has been used at Atsuta Shrine since. Even the Emperor himself, by most accounts, does not view the objects directly during accession rituals, encountering them instead through their ritual wrapping, which if accurate means the tradition's central claims are unverifiable in principle rather than merely unverified in practice.

This is a genuinely different situation from a contested relic such as the Shroud of Turin, where testing has occurred and produced disputed results; here, no testing has been permitted at all, so there is no scientific dispute to report, only a religious and state tradition maintained by consistent non-disclosure. The atlas records the transmitted tradition as tradition, and notes plainly that no independent confirmation of the objects' age, material or even continued existence in their originally described form has ever been possible.