What is the truth of the Mizuage? Did it involve sex or not?

Question

There is much controversy other the truth of the Mizuage Geisha ceremony. Films like Memoris of A Geisha depict it as a sale of one's virginity, this is also supported by others. However it has also been stated that this is not the case. Especially by Mineko Iwasaki (who was a real geisha heavily interviewed for the book and then movie). However she was a fairly recent Geisha.

What is the truth?

Answer 1

It involves a Geisha for sure losing her virginity via a bid for her virginity.