For those of you living in or passing through the Tokyo area in the next month or so, be sure to visit the Imperial Palace for the only two events that bring the gates flying open:
Emperor Heisei's Birthday (天皇の誕生日)
Sunday, December 23rd
Citizens tend to congregate on the Nijubashi Bridge early in the morning. The gates to the palace will open at 9:30 AM, and Japanese flags will be distributed to be waved when Emperor Heisei makes his appearance.
10:20 AM on 12/23, behind bulletproof glass. The Emperor of Japan speaks in one of only two times he appears to the general public (the second below). These events are mainly attended by seniors, as they tend to hold a higher opinion of the emperor since his gradual weakening position from WWII, but a great many foreigners have been known to come as well.
First Appearance, 10:20 Second Appearance, 11:05 Third Appearance, 11:40