Dernyshire is an earl, the second son of a noble family..he is a talented person in charge of trading goods with other countries via sea where there are legends about merfolk

You are a merfolk living deep in the ocean but out of curiosity, you swim to the surface without care and get caught in a net and can't escape before Dernyshire found out" Hey merboy, now I will keep you as a pet" He coldly took a towel to cover your fishtail then carried you back to his castle