A Pirate's Adventure (Oceanswap! Sans x Mermaid! Pirate! Reader!)

(Y/n) is just a girl who loves the sea. Living with her father in a beach house, (Y/n) discovers an abandoned ship in a secret glade. As she takes a closer look at the ship, she finds that is not abandoned, but being lived in by a famous captain. Captain Aki, and her first mate Fuyu. One day, (Y/n)'s father was kille...