In pre–World War II history, the term "onsen geisha" had a negative connotation, as geisha who lived and worked at hot spring resorts or towns were often regarded as the lowest of geisha, they were unbound by contracts and could move to any other onsen town, and thus had no "history" or professional genealogy. During this period, some onsen geisha were sponsored by businessmen who made yearly visits; these patrons were known as danna. Sayo Masuda, an onsen geisha in the late 1930s and early 1940s and author of Autobiography of a Geisha, the first book of any kind about the geisha lifestyle, wrote that a typical geisha's contract was bought out by a danna for about 30 yen and never for more than 100. Interaction with other customers beyond party entertainment was common; therefore, the concept of onsen geisha as prostitutes was not entirely incorrect in pre-World War II days. Sayo Masuda wrote that onsen geisha in this time would be taught some traditional geisha skills, but were also frequently pressured into having sex. Graduation to full geisha status for onsen geisha always involved mizuage - losing one's virginity to one's danna or another paying customer - and unscrupulous okiya mothers could sell a girl's virginity a number of times to customers who would be none the wiser. Geisha would compete amongst themselves for their standards and who they would sleep with, but, as Masuda details, this likely originated from making the most of a sometimes poor and exploitative situation, in some ways further bolstering the perception of onsen geisha as prostitutes:
Karuta was a first-rate Elder Sister: she had standards and would never sleep with any man other than her danna. This was not from a sense of feminine virtue; it was a sad sort of pride. This "geisha's pride" wasn't worth a broken straw sandal, of course, but - under the influence of Karuta, I suppose - its hollow conceits took root in my mind.
Masuda notes that many onsen geisha of this time has serious problems with alcohol due to the sake drinking contests which frequently formed a significant part of their work through parties. Drinking problems frequently persisted in many onsen geisha even after retirement.
Post-World War II
In the period following World War II, the abundance of prostitutes in onsen towns such as Atami marketing themselves to American GIs and tourists as "geisha" led to misconceptions surrounding geisha and sex workers. Many foreign visitors to Japan, unfamiliar with the traditions of appearance separating geisha from sex workers, were unable to distinguish between the two, as both wore kimono and were seen to entertain men. Following the passing of the Prostitution Prevention Law in 1956, and its enforcement in 1958, onsen geisha were no longer legally able to practice sex work, and modern-day onsen geisha are not sex workers. Geisha banquets in onsen towns are markedly different from geisha engagements in the more traditional hanamachi of Kyoto and Tokyo. Whereas geisha parties in Kyoto are usually small affairs in teahouses with five or six geisha, onsen geisha usually entertain tourists in the banquet halls of large hotels, often with 60 or 70 geisha in attendance. Instead of being called to teahouses and parties around the area by customers who likely already know them, onsen geisha are employed to work at one establishment, likely a hotel in the area, and are called upon by guests who do not know them, paying for a dinner or party with geisha entertainment. Geisha are contracted to work for only a certain amount of time based upon the paying customer, and unlike other geisha parties, leave when this time is up. The modern surge of tourism, expendable income, and capitalisation has caused onsen geisha, who historically entertained groups similar in size to those in Kyoto and Tokyo, to increase the size of parties to larger and more profitable banquets such as these. In Atami, the official registry office regards long-time, proven geisha as separate from those who have not yet completed their first year.