The Kubizuka at Ōtemachi: Why Has the Head Mound of Masakado Remained in Front of Tokyo Station for a Thousand Years?

Five minutes on foot from Tokyo Station. In a corner of Ōtemachi in Chiyoda Ward, surrounded by high-rises, is a space entirely out of proportion with its surroundings.

Taira no Masakado's Kubizuka (Head Mound). The place of tradition that in 940 Masakado's head, exposed in Kyoto, flew eastward and fell here.

The surroundings are one of Japan's representative financial districts, but only this one block retains old trees, a stone monument, and the sky.

The Shōmon-ki and later Edo-period tales transmit that Masakado's head, after being exposed in Kyoto, flew eastward in search of its home Kantō and fell in the Toshima District of Musashi Province (the modern Ōtemachi in Chiyoda Ward).

There is no corroboration in contemporary sources; it is a tradition formed within the Masakado cult in the later Kantō.

But the fact itself that this Head Mound has continued to be preserved for over a thousand years as an actual historic site at the center of Tokyo does not move.

In modern Tokyo urban development, plans to relocate the Head Mound have been raised several times.

Post-1923 Great Kantō Earthquake recovery plans; postwar plans by the General Headquarters of the Allied Powers (GHQ) to turn the site into a parking lot at the time of requisition; later Marunouchi and Ōtemachi redevelopment plans.

But each plan is said to have been canceled or delayed by events regarded as 'curses' — accidents, sudden deaths of those involved, breakdowns of construction machinery.

Elements of urban legend are included, but as fact the Head Mound is still preserved in its original position.

For contemporary Japanese, the Head Mound functions not merely as an ancient historic site but as another space within the city.

Worshipers among the people working in the surrounding office district are constant, and memorial services are held on the anniversary of Masakado's death.

The historical fact-status does not exceed tradition, but the fact itself that the Head Mound has continued to be an object of popular Kantō belief for over a thousand years speaks to the historical weight of the figure Taira no Masakado.

A rebel of Kantō who defied the central regime, still worshiped in the modern center of Japan — this structure is a rare case in Japanese cultural history.