Of the many places of burial practices in Japan of the medieval periods, Fukyama Toshio contributed to the finding of this mummy. The reports consist of seeing a mummy in the Joshin'an temple located in Yonezawa that has been buried in 1892 during the digging of the grave.
Baishinni mummy was found next to a small container for holy relic with the name "Nun Baishin" graved in it. Turns out this was the mother of Sato Tosinobu, a close family member of Hidehira.
Studies show that this mummy was one of the first mummies buried in the eighteenth-century.
There have been no specific indication of the cause of death of this mummy.
Hiraizumi: Buddhist Art and Regional Politics in Twelfth-century Japan