Chapter 609: Adventure on Fish-Man Island

Sanji plays in the cove pool with the mermaids while Luffy dips his feet nearby. Chopper mentions that Sanji's rare blood type, S RH-, has run out in their stock. Luffy tells Camie he wants to meet Jinbe, who helped him through the death of his brother Ace. Camie explains that after Jinbe gave up his Shichibukai title during the war, he and his crew could no longer remain on the island, so Luffy cannot see him there. She adds that the war changed many things on Fish-Man Island.

The Medaka Mermaid Quintuplets warn that a royal ship is approaching, possibly to arrest Luffy. He, Usopp, and Chopper hide among the rocks while a mermaid shields Sanji in the water. Aboard are King Neptune's three sons, named Fukaboshi, Ryuboshi, and Manboshi, who have come in person to chase down a report of illegal entry. The mermaids cover for the crew, and the princes prepare to leave, until Sanji, with his head pressed to a mermaid's chest, erupts in his most enormous nosebleed yet. The blood loss leaves him minutes from death.

Chopper begs for an S RH- donor, and Camie confirms that humans, merfolk, and fish-men all share transfusable blood. Hammond intervenes with laughter, declaring no one on the island would give blood to a human, citing an old human-made law forbidding the mixing of bloodlines. He reveals that Fisher Tiger himself died because humans refused him a transfusion, then names his boss as Hody Jones. When Hammond fires a net at them, Luffy sweeps it aside and drops Hammond and his accomplices with Jet Pistols, cowing their sea monster with Haoshoku Haki. Camie hijacks the royal gondola to rush Sanji to town, while back at the cove Fukaboshi laments that they have lost their chance to deliver Jinbe's message.

Mermen make their debut, and the ruling family of the island is seen for the first time. Camie reveals that Jinbe and his crew departed once he stepped down as a Shichibukai during the war with Whitebeard. Sanji suffers a critical, near-fatal nosebleed, and his rare S RH- blood type is disclosed. The blood of humans, merfolk, and fish-men is shown to be compatible across all three. Per Hammond, Fisher Tiger died from a refused transfusion. Hody Jones is given as the name of the crew leading the New Fish-Man Pirates, and the Neptune brothers turn out to be Jinbe's allies, holding a message meant for Luffy.

The blood-sharing ban between humans and fish-folk was, ironically, imposed by humans long ago out of fear of the fish-men, meant to prevent mixed bloodlines. Camie also notes that no humans besides the Straw Hats have visited the island in roughly a month, with rumors that someone may be manipulating events behind the scenes. Caribou's sealed barrel is glimpsed at the cove, its occupant listening intently.