Masakadozuka or literally Masakdo’s mound is located at Tokyo’s Otemachi District , a few minutes walk from Tokyo Station .
Taira Masakado was a feudal lord during Japan's Heian Period ( from 794 until 1185 ), descended from the Japanese Imperial family , that lived in the Kanto region from the year 903 until his death in the year 940 . Taira Masakado lived a tumultuous life fighting wars motivated by either Personal Prestige and Power or love relationships . In Masakado's final years he lead an insurrection against the Emperor , after claiming to be the new Emperor himself . Masakado was defeated and beheaded in Kyoto .
Masakado is considered to be one of Japan's 3 great onryo . " In Japanese traditional beliefs and literature, onryō (怨霊, lit. 'vengeful spirit', sometimes rendered "wrathful spirits", "hatred spirits", "resentful spirits", "ruthless spirits", "envious spirits", "dark spirits", "fallen spirits", or "downcast spirits") are a type of ghost (yūrei) believed to be capable of causing harm in the world of the living, injuring or killing enemies, or even causing natural disasters to exact vengeance to "redress" the wrongs it received while alive, then taking their spirits from their dying bodies ".
The frogs on each side of Masakado's tomb reflect his desire to be laid in rest in his homeland . The frogs , 蛙 ( Kaeru ) in Japanese , is a word pun , also meaning to return . Legend says that after Masakado was beheaded in Kyoto , his body and head were engulfed in bright light and flown into the skies headind towards the Kanto region . It's said that his body felt where Kanda Shrine is located today and his head in Tokyo's Otemachi district . A tomb was erected in the place that his head had fallen . It's said that in the middle ages this tomb had fallen into disrepair , which coincided whith some severe natural disasters that were happening in the region . People in the neighborhood associated such natural disasters with Masakado's tomb state of disrepair . From this time on Masakado's tomb was taken care of with dutiful respect .
Fast forward some centuries and after the 1923 Great Kanto Earthquake , Japan's Ministry of Finance decided to build a provisory office building over Masakado's tomb . What succeeded in the following years were a series of incidents , including the deaths of people related to the construction of the site , the sudden death of a Finance Minister and the building being struck by lightning and catching fire . Besides these incidents being reported in the Japanese media , there were also rumors between the Ministry's employees about the building being haunted by Masakado's ghost .
After WWll ended there was the epidode in which there were plans to build a parking lot over Masakadozuka for the GHQ of the US Occupation Forces in Japan . What followed were a series of unexplained accidents including one in which a bulldozer from the US Armed Forces overturned and the driver died .
Masakadozuka's upkeep has been the responsibility of an organization named Society for the Conservation of the Historical Site Masakadozuka . It's comprised by big corporations such as Mitsubishi Real Estate , Takenaka Corporation and Mitsui Real Estate , among others and is supervised by Kanda Shrine .
The most recent incident happened on August 19th 2026 , when a man belonging to a streaming group got over the stone monument and streamed live from Masakadozuka . This person was later arrested . What happened on the following days got the Japanese media's attention once more . On August 23rd there was an earthquake at a location where Masakado's feudal domain used to be . There were also torrential rains in Tokyo with some floodings in some locations . Some people associated such incidents with Masakado's ghost .
Masakadozuka's actual appearance was given after the 6th Renovations Works were finished on 2021 . Over the centuries Masakadozuka has shifted from a place related to unfortunate events into a worship place for Tokyo's Guardian .