Masakado’s Mound (Masakado-zuka)

Taira no Masakado was a 10th-century warrior of the Kantō who rose against the imperial court in Kyoto, declared himself a “new emperor” of the eastern provinces, and was killed in battle in 940. His head was taken to the capital to be displayed. According to legend it would not rest: it flew back east and came down in the fishing village of Shibasaki, on the shore of what would become Edo and then Tokyo, where local people buried it. The mound that marks the spot now stands in Ōtemachi, among the glass towers of Tokyo’s financial district, facing the Imperial Palace moats.

From early on Masakado was feared as an onryō, a wrathful spirit, and also honoured as a protector of the eastern people who had defied distant rulers. Chiyoda City’s local-history archive relates that disasters around the mound were blamed on his anger, and that in 1309 he was enshrined as a deity at the nearby Kanda Myōjin shrine to calm him. When the shogunate moved Kanda Myōjin to its present site in 1616, the mound stayed where it was, in the grounds of daimyo mansions and later, from the Meiji era, in a courtyard of the Ministry of Finance.

The modern legend of the curse dates from the 1920s. The Great Kantō Earthquake of 1923 wrecked the ministry and damaged a memorial stone erected on the mound in 1906. During rebuilding, a temporary office was put up over the courtyard and the mound was cut down. Then, in 1926, the serving Finance Minister died, and staff and workers suffered further deaths and injuries. These were attributed to Masakado; the temporary building was removed, the mound restored in 1927, and the memorial stone re-erected in 1940. Later tellings add that heavy machinery overturned when US occupation forces tried to clear the site after 1945 – a story repeated widely but not documented.

Today the site is cared for by the Shiseki Masakado-zuka Hozonkai, a preservation society made up of Kanda Myōjin’s chief priest and neighbouring companies, which holds memorial rites. It was renovated between November 2020 and April 2021 alongside the Otemachi One redevelopment; office workers still stop to bow and leave water, flowers or sake, and frog figurines are left as offerings because kaeru (“frog”) also means “to return.” It is a place of worship first, and visitors are expected to behave accordingly.

Rather than apparitions, the mound is known for a curse: misfortune, illness and accidents said to befall those who disturb or disrespect it, from the 1920s Finance Ministry deaths to rumours about nearby offices whose desks are never placed with workers’ backs to the mound. Some visitors also describe a heavy or tense atmosphere at the site.

The mound and its stone monument stand in a small walled enclosure in Ōtemachi 1-chōme, near exit C5 of Ōtemachi Station. Masakado is also enshrined as a deity at Kanda Myōjin, about 2 km to the north.

Masakado’s curse looms over modern Tokyo fiction, above all Hiroshi Aramata’s novel Teito Monogatari (1985–87) and its film adaptation, and he appears in manga, anime and the Megami Tensei games. Masakado is honoured at Kanda Myōjin, one of Tokyo’s most important shrines, and in festivals such as Sōma Nomaoi in Fukushima.