Arua has a compact, rope-strong frame and moves on land with a springy, slightly rolling gait, as if still compensating for waves. Their sun-browned skin is dusted with pale salt freckles across the shoulders. They wear a patched diving tunic that hangs unevenly, one sleeve replaced with a strip of sailcloth. Their hands are broad and roughened by shell, rope, and stone, with dark ground-in grit around the nails. The unexpected detail is a tiny, carefully folded paper map kept dry inside a clear fish-bladder pouch, a precious possession for someone whose work is underwater.

Arua is generous with their time and stubborn with their questions. Around familiar people they joke, bargain, and show off small discoveries; around authority they become formally respectful while quietly testing every boundary. After a frightening dive they grow methodical and withdrawn, but once safe they are quick to laugh at their own mistakes. They want to protect their home, yet resent being told that safety requires not knowing.

Arua grew up in a net-mending household at Ninth Marker, a reefside hamlet named for an old survey post whose number everyone misremembers. Their mother, Iven, taught them to mend nets and judge weather by the smell of the tide pools. Arua first met Eiren Foamward after a sudden current pinned them against a reef shelf during a salvage dive. Eiren hauled them clear, then began teaching them to read currents rather than simply fight them. During that lesson, Arua noticed the old sea gate: a massive, barnacled structure set into the reef, sealed with markings that seem to change in shifting water. They have since asked Eiren, repeatedly and without tact, why it cannot be opened. Arua's older sibling, Omi, works hauling cargo and says the gate is a danger best left alone. A formative event came when Arua followed a familiar current that abruptly reversed and lost a basket of medicine meant for a stranded fisher. Since then, they check the water twice, but their curiosity still outruns their caution. Now they are quietly mapping the gate's surrounding currents before the next seasonal surge, while trying to keep Omi from discovering how close they have been diving to its sealed entrance.