Originally, Courtesan was a Lander-only occupation that was seen in a quest, but later updates allowed Adventurers to obtain it as a subclass. In the original quest, there was a princess and a pauper who looked uncannily alike, and both craved the life of the other. By chance, they met, and the princess took the pauper into her home, and they switched places. However, the pauper ended up being killed by assassins—but her occupation was Courtesan.
Using its historical connotation rather than its modern suggestion, Elder Tale Courtesans often act as escorts to nobles and are able to influence them politically or even economically. This subclass was added on a whim by the F.O.E. devs in the expansion pack before Homesteading the Noosphere, so there is a likelihood that this subclass only exists on the Japanese server.
Courtesans are skilled in classical skills, such as poetry, music, and dancing. They are adept at the art of conversation and the tactics of love. They are the opposite of "ideal love," as their existence revolves around selling love and dreams. For Lander nobles, having a courtesan as a partner in dancing socials is a kind of status. Courtesans compete with each other for popularity with the nobles, inspiring both respect and jealousy.
With Adventurers, this relatively new subclass isn't very popular and is still largely a mystery. What is known is that they are adept at negotiation, have discounts when purchasing rare items, and receive [Probably as in Cash Shop items] from patrons when making zone purchases.