There are two merfolk. This kid is the mermaid's younger brother. He IS a lot older than he appears (in humam terms), but it's kinda like how elves have a longer lifespan, so a 100-year old elf is equivalent to a 10-year old human. Merfolk in this story are similar.
Pretty sure the kid is the younger sibling, the one that wants to learn about human and the surface world. I don’t know about their gender though
There are two mermaids, the princess Aria and her brother Iser(Eunha). They are both older now but Iser took the form of a child to infiltrate the church
Yo I'm kinda confused out here I was thinking this merman kid is actually a grown ass mermaid girl pretending to be a kid. As I read the back story there's this mermaid girl observing them, is this kid actually a girl or I'm I tweaking?