Sugita, who started the study in 1914, located a passage that said, 'A note about an occurrence in Kasuga four villages in 1428 was found on the surface of the Jizo rock,' in "Yagyu-ke Zakkiroku" (Miscellanea of the Yagyu family) written by Shirobe MATSUDA of the Yagyu clan in the Kyoho era, and later in 1924, he advanced an opinion that it was a relic of the peasants' uprising of the Shocho era.
大正3年から研究を開始した杉田氏は、享保年間に柳生藩の松田四郎兵衛が記した『柳生家雑記録』に「地蔵石に天長元戌申年春日四箇郷の事書付有」とあるのを確認、その後、大正13年に正長の土一揆の遺物説を唱えた。