sorry. only easy explanation.
HISTORY OF IWAKUNI STONE DOLL
stone doll are small natural items attached
to stones in the river under Kintai Bridge.
Because the shape is like a doll, it is called
stone doll.
A folk tale says : long ago, when Kintai
Bridges was constructed, two young girls
was offerd as a sacrifice for smooth
constructionof the bridge, and that the stone
doll is a rebirth of this girl.
Also, because humen sacrifices were made
to protect bridges and castles, these dolls
were used as amulets to protect
oneself from accidents, disasters and evils.
Further, they were used as folk toys, and
it is said to be one of the three rare toys
of Japan. During the latter part of Edo period,
Many poems were composed about this stone
doll and a culture Peculiar to Iwakuni was
developed.
Originally, this stone doll is a nest made
of pebbles and sand collected by an insect
of a mole cricket family.
It has been introduced widely throughout
the country as a very rare article of folk
art of Iwakuni.