Was looking at these two circles on Yoshiro's forehead. I really think Yoshiro and Soh descended as One and then are separated into two during the ceremony and ritual.
The two circles may represent they're two as one.
They frequently act in union, too.
Or, if we consider the other theories like new Maiden every cycle, are there how the new Maiden is found? Is the Maiden born with them as a way to show she is the chosen one?