The tumulus was designated a National Historic Site of Japan in 1949, with the area under protection adjusted in 1984.

[1] It is one of the largest circular tombs in Chikushino, dating from the late Kofun period (6th century).

The designs are painted in red, black, and green and depict people, ships, cavalry, houses, horses, snowflakes, animals, and concentric circles, but many have faded and is now difficult to decipher.

[2][4] Due to grave robbing, very few grave goods remained, but gold rings, pipe beads, magatama beads, swords, and Sue ware have been collected.

[2] The site is approximately a ten-minute walk from Harada Station on the JR Kyushu Kagoshima Main Line.