Shirahoshi

Shirahoshi is a giant mermaid, roughly the bulk of her pet shark Megalo and only a little shorter than her father, which leaves her many times the height of an ordinary human like Luffy. Long, flowing pink hair spills down her back, pinned by a clip shaped like a custard-filled taiyaki, and her broad-striped tail finishes in a ruffle near the waist. She wears a pearl-covered yellow halter top, clam-shell earrings, and a chained loincloth, and shy blush often colors her cheeks. Her beauty is famous enough to be likened to Boa Hancock's.

Despite her enormous frame, the princess has an exceptionally timid nature and bursts into tears at the slightest upset, having been thoroughly pampered by her family. She is unfailingly polite, attaching an honorific to everyone she addresses, and her decade of seclusion leaves her curious yet naive about the world above. Most of all she is gentle and forgiving, holding no hatred even toward those who harm her loved ones; she keeps the identity of her mother's killer secret to honor Otohime's dying wish, a resolve that deeply moves Jinbe. When her people are threatened she finds genuine courage, and by the time the Straw Hats sail away she resolves to outgrow her tearful habits.

Serving as the living embodiment of the ancient weapon Poseidon, Shirahoshi can call the gargantuan Sea Kings to her by emitting sonar-like waves when she cries out, a gift handed down from her ancestor. The World Government dreads this power, since in the wrong hands it could plunge the world beneath the waves. She first triggers it unknowingly as a child and later fully awakens it while begging the Sea Kings to come rescue Noah and Fish-Man Island. Her giant size also lets her swim faster than nearly anything in the ocean and lift a full-grown person in a single hand, and like her mother she carries the potential for Observation Haki, even if no use has surfaced on the page.