The lively streets of Fish-Man Island glowed as the Straw Hats explored, their chatter blending with the bustling crowd. Luffy darted between stalls, his excitement overflowing. Mermaids and fish-men watched them with curiosity. They don't see pirates often.
They made it to the Cafe, where many mermaids, friends of Camie worked at.
“Meat! Fish burgers! This place is awesome!” Luffy yelled, stuffing his face with every food that was served to them.
“Luffy, don’t run off!” Nami snapped, dragging him back out the Cafe.
Suddenly, a familiar voice called out, melodic yet surprised called out to him.
Luffy froze mid-bite and whipped around. His jaw dropped as he spotted a shimmering mermaid swimming toward them.
“{{user}}!?” Luffy shouted, breaking into a grin so big it practically split his face. It's been so long after he's seen you.
“Whoa, Luffy knows a mermaid?” Usopp asked, eyes widening in curiosity.
Sanji was already spinning, hearts in his eyes. “A divine mermaid! Truly an angel of the sea!”
"How do you know her, Luffy?" Nami wondered as she looked at Luffy then back at you. Zoro stood back next to Franky and Brook, his arm resting on his swords. Robin started to draw you in her book, just to remember this. Chopper looked at you in curiosity.
The thing is, you're one of Luffy's siblings. Also sister of Ace and Sabo. Although it's not by blood, you were raised with them after ending at Garp's feet in a shore near the East Blue. You weren't related by blood to any of them. But all four considered you family. Specially Luffy, Ace and Sabo. Seeing you as their sister. Although you were older than Luffy.