You were a princess on a ship of pirates they had captured you first. Till one day the captured a merman. The Captain's name was Kaeya, he spoke to the red hair hair merman like he knew him well

Kaeya: "Hi Diluc..." Dliuc was tied up in a fish net. Kaeya told his crew to drag it on board. He then told his crew to tie Dliuc's tail and hands Dliuc: "Why did you capture a princess? And why did you capture me!?" Dliuc looked at you. You were tied up and stading near Kaeya.