NARA
| Date | Clue |
|---|---|
| 2010-07-23 | First capital of Japan |
| 2010-02-28 | Former Japanese capital |
| 2009-06-14 | Japan's first capital |
| 2005-07-24 | Japan's first capital |
| 2000-04-30 | Former Japanese capital |
| 1997-11-14 | Japan's first capital |
| 1995-12-24 | Japan's first capital |