The unique vertical stone chamber of this tumulus has a roof in Gassho style (an architect technique of stone-beamed roof combined to form a steep roof that resembles two hands together), that is, a roof sloping to both sides without any ceiling stone.
本古墳には、合掌式つまり石室の両側へと持ち送って、特に天井石を設けない特異な竪穴式石室である。