I knew Niigata once had a geisha community, but I didn't know it still did. That's great to hear! Thanks for the link. I'll have to add the info if I revise this post in the future.

The pronunciation sent me down a rathole. So niigata didn't use the Edo word 芸者 but continued to use the kansai 芸妓. It seems the 妓 in 芸妓 was standardized to ぎ by the Meiji government in 1872. Kyoto stubbornly clung to calling them げいこ, while Niigata and other areas adopted the new official reading, げいぎ, in an effort to sound more modern and aligned with national standards. Interesting!