User blog comment:Ghmorello/Chapter 927: Wano's Next Top Geisha/@comment-2606:A000:1019:867F:C1D5:4C16:4DF8:CAD9-20181211010355

Komurasaki is Boa Hancock. She's in Wano to assist in the fight with Kaido. I don't know if Luffy called her, or someone else called her, or if she came on her own. Hancock is the only character beautiful enough to match the way the old shamisen lady described Komurasaki, and Oda was rather coy by revealing only part of her face instead of keeping her appearance entirely concealed.