Geisha as a 5e Bard College of Glamour variant
by Marc SaindonThis comes with the caveat that I'm not thrilled about a "concubine" class (Saloon Gal archetype from Deadlands...), or the intepretation that their "knowledge of anatomy" allows them to work as Rogue and get a sneak attack bonus to attacks when striking vital points. So the concept of Geisha as I'm proposing excludes "lady of the night" work and sticks solely to the hostess/performance artist role : she'll organize a tea ceremony, sing, play violin or the ocarina, and even create poems about you and your party members after that big fight against the villain of the week, but things end at PG-level. The show Firefly did a good job walking the fine line with the concept of Companion, but still not everyone is going to be okay with the idea of roleplaying a certain interpretation of Geisha in pop culture.
Of note is that "The first female geisha appeared in 1751, with geisha before that time being male performers who entertained guests. Only later did the profession become mainly characterised by female workers". So the profession of Geisha covers male characters as well (do we say Geisho?).
If you import the Al-Qadim's Station rules (which sets up your character of the ladder of classes and castes), attending a ceremony hosted by a Geisha could be a means to conserve or increase your Station, especially if the hosts are given substantial tips and gifts. These ceremonies can seal contracts or alliances, or break them if a character behaves crassly.
As a PC, a Geisha or "Geisho" would have a predominantly social and political role, capable of breaking or making reputations.
Notes:
Geisha
(Image from: https://www.deviantart.com/gekata23/art/Fox-geisha-459144577)