[1] The tumulus was discovered October 1970 when villagers dug a hole to store ginger and found old cut stones.

Due to its small size and lack of historical documentation, the tumulus was regarded as unimportant until the horizontal entry stone burial chamber was opened, at which time it was realized that this was a decorated kofun.

The burial chamber is made of cut tuff stones, has a passageway on the south side, and is long in the north-south direction.

The murals are on the east, west, north (rear) walls, and ceiling of the chamber, and are painted in fresco on top of a layer of plaster several millimeters thick applied to the cut stones.

The subjects of the murals are human figures (groups of four male courtiers and four serving maidens in Goguryeo-style garb), the sun, the moon, the four gods, and the stars (constellations).

It is highly likely that the Vermilion Bird, the southern of the four gods, was painted on the south wall, but this is thought to have been lost during tomb robbery in the Kamakura period.

For whom the tomb was built is unknown and has been the subject of much speculation, but the decorations suggest it is for a member of the Japanese royal family or a high-ranking nobleman.

The unusual preservation method is being considered because the tomb's current situation makes it impossible to prevent further damage and stop the spread of mold.