This is a topic that is very confusing to a Western audience and questions about it come up enough that I figured I’d write about it to clear things up.
So, what is a “Danna” (旦那) exactly? In short, it is a person (traditionally male) who sponsors their favorite geisha. Sex was never expected as part of the deal, but if it happened then there was no taboo against it. Danna informally means “husband,” but that role is no where near what we’d equate with a husband today. Being a danna was a business transaction and you were, in a sense, “married” in that one geisha could only have one danna and one danna was supposed to only have one geisha (there are people who will always break the rules, and when women found out that their danna was a patron of other geisha it could get ugly!).
Back in the days when all geisha were expected to have a danna (and they did), the stories of men running off with their geisha mistresses didn’t really happen as much as you’d think. If she was very beautiful and he was very young then he may pay her debts and marry her, but an older man wasn’t looking for a teenager, and this is where the most competition occurred. To have a danna back then meant that a geisha had one specific man who bought her luxurious items (new kimono, kanzashi, etc.) and, in return, he would be known for his “patronage of the arts” as men competed to have the most popular geisha as theirs. Everyone was a patron of the geisha - from the lowest social class (the merchants) to the highest (the samurai) and, unlike the outside world, the karyūkai was a fabulous show of wealth that was not nearly as restricted by the government as it was outside of it. It may seem a bit backwards to us today, but the merchant class was by far the richest social class in the Edo Period even though they had the least prestige and literally the worst ranking. Since merchants weren’t allowed to buy very nice goods (well, better to say that they could, but that they’d just have to hide them) they could buy the patronage of the most famous geisha, and the most famous geisha were household names across the entire country. It was no secret when it came to which geisha had which man for a danna, and the danna himself would often use his geisha as an investment for his business.
By being a danna you reaped many rewards, even though the sums of money you were paying were, shall we say, pretty damn high. Have an important business meeting? Call your geisha over to entertain your guests. Not only will your guests recognize her if she’s very popular, but she is known for her secrecy and no business dealings will ever leave that room. Going to a sumo match? Bring your geisha and show her off to the entire city. Rumours would spread like wildfire about So-and-so who was the danna of Geisha-X, and this usually brought the man more business dealings. By retaining such a popular geisha, to which this man would be paying enormous sums of money (sometimes most of the business’ income!), he was seen as trustworthy since he has shown that he deals well with money and makes quite a large amount of it.
This is where most people are like, “he paid that much money and there was no sex!?” Yes, that statement is correct. By law a geisha was not allowed to exchange money for sexual favors as legally only the yūjo (prostitutes) were allowed to do so. This wasn’t as cut and dry in “double registered” areas, but most of those were in small towns as geisha in the big cities prided themselves on not selling their bodies. Still, prostitution has always been seen in a very different light in Japan than it has in the Western world. Marriage used to be a business transaction between two families and the only thing that was actually expected of them was to have children. Beyond that, the man was free to work (and play) how he wanted in the realm of business and the woman was master of their domain. For a man having sex with his wife was seen as a duty and rarely was it ever for pleasure. If he wanted to experience pleasure in a sexual encounter he’d go to a yūjo and money would be exchanged for that service. The wives were not jealous (well, not meant to be) as a man having “fun” with a yūjo was a business transaction. A man being a danna to a geisha was just the same and it had no bearing on the official marriage itself.
Today most geisha do not have a danna as the traditional danna system has mostly faded away due to transitioning times. However, the current system is one that’s equal to “multiple danna,” that is, more than one person can sponsor a specific maiko or geiko. She likely won’t be paying for all of her luxury items with this money, but it does add up if she has more than one and this still provides bragging rights to the danna themselves.