This is a partial declassified summary. The original record (NR-0018, Japanese) remains under access restriction.

The document was received on December 1st, 2023, at midnight JST. Origin unknown.

The content describes a series of written communications delivered to an address that no longer exists. The building in question was demolished in 2013. Postal records confirm that the address was decommissioned at that time.

The letters, however, continued to arrive.

Recipients reported identical handwriting across all correspondence. The paper showed no signs of aging. The postmarks bore dates ranging from 1987 to 2011 — all predating the building’s demolition.

The most recent letter, reportedly received in November 2023, read only:

“I kept writing. I did not know you had gone.”

Sender identity has not been established. Investigation ongoing.

Access to full Japanese source record NR-0018 requires Level-3 clearance.