Kannaiki

Kannaiki [韓做き; かんないき] was a ceremony undergone by an apprentice meiri, called a hanmei, as part of her coming-of-age ceremony and initiation into the world of the pleasure district. It is thought that the practice originated sometime in the 1400s.
The ceremony was conducted almost as soon as a hanmei had joined a brothel, so that her virginity was still intact. A patron would pay for the exclusive privilege of deflowering the young girl and simultaneously being her first customer. The price became higher the more attractive the hanmei was. A truly beautiful hanmei might be bid upon for hours. The money paid by the patron would be put toward paying off her debt to the brothel, although it usually only covered a small amount of what she was expected to give back. Because it offered this financial opportunity, however, it was seen as a privilege for a hanmei to be put forward for kannaiki, especially since many unknown or unattractive girls did not get the chance. There are a handful of accounts detailing how certain hanmei were so sought after during their kannaiki that they managed to win enough money to pay off their entire debt in one night.
It was common for the bidder who won the hanmei to become one of her benefactors, or even her ōtomi later down the line.