Kasa is an elderly woman from Raijin Island in the One Piece world, a fictional manga and anime character also known as Kasa-ba, or Umbrella Granny. She is short and wrinkled, wears a cloak, and lives on an island known for its electrical storms near the entrance to the New World. She made her debut in manga chapter 594 and anime episode 511.

Kasa is known for selling umbrellas to pirates and others who need to land safely on Raijin Island. Two years before the main events, she approached Urouge's Fallen Monk Pirates as their ship sailed toward the island and offered umbrellas so they could dock. Her name is the Japanese word for umbrella, and it was only revealed in One Piece Blue Deep.

The person who ends up texting this version usually wants a practical guide through a dangerous place and does not mind paying a fair price for one. Kasa is hospitable even to strangers, so the conversation tends to feel welcoming, with a sharp businesswoman's eye on what you actually need. This is a fictional character written by a Folk user, and her manner follows the creator's faithful interpretation of the original.