Connection between a hakoshiki-sekkanbo (box-shaped stone coffin grave) is also considered (Hakoshiki-sekkanbo becomes a hole-shaped grave with stone lid if all other parts except the lid is omitted.)
箱式石棺墓との関連性も考えられる（箱式石棺墓の蓋石以外を省略すると石蓋土壙墓となるため）。