Chapter 612: Taken by the Shark They Saved

A flashback returns to Mermaid Cove, where Ishilly pries open Caribou's barrel expecting expensive liquor. Caribou bursts free, thanks her, and turns his lower body into a swamp using the Numa Numa no Mi, sinking and silencing the three mermaids in a bottomless bog he says is impossible to escape. Reverting to human form, he gleefully realizes how much the mermaids could fetch at auction and credits the Straw Hats, whose illegal entry let him slip past immigration to hunt freely.

Carried up to the palace on Megalo while Neptune rides Hoe, the crew listens to the king explain how the captured kraken nearly cost his daughter her beloved pet. Luffy repeatedly calls Neptune grandpa, exasperating Pappag, while Nami asks why the island glows so far below the surface. Neptune credits the Sunlight Tree Eve, whose roots carry surface light and air down to the seafloor.

Inside the palace, two ministers berate Neptune like a child for wandering off alone, and the king learns that it has happened again with his daughter. Drawn by a delicious smell, Luffy slips away from the group and follows his nose to a massive iron door studded with embedded swords and an axe, which he mistakes for the dining hall. He pushes through into a dark room, spots food, and crashes into what he thinks is soft coral, bouncing on it like pudding.

A light flicks on and Luffy tumbles down beside a gargantuan smelt-whiting mermaid, the Mermaid Princess Shirahoshi, having been climbing on her body. Terrified, she insists she is not afraid and is Neptune's daughter, yet bursts into tears so enormous Luffy must dodge the droplets while protesting that he never did anything to her.

Caribou's Logia fruit is named the Numa Numa no Mi, and Megalo is revealed as Shirahoshi's pet. Pappag's claim of friendship with the princess is exposed as a lie, and the whereabouts of Zoro, Robin, and Franky are confirmed. Neptune's two ministers and Shirahoshi are introduced, and Luffy's 400,000,000 bounty appears on a poster for the first time. Like the Water 7 arc, the crew is wrongly blamed for the island's chaos. The chapter belongs to the Fish-Man Island arc.