Huang is an early face in Eiyuden Chronicle: Hundred Heroes but a later recruit. When talking with him you'll see how easygoing and peaceful he is, which is fitting for his fisherman lifestyle he looks to add to your team.
When you first see Huang, he is in Arenside and gives you a bamboo rod you can use for fishing. Later, you use this same rod to get him to join the Watch. You will run into him in the southwest part of Hishahn and he will request a Wheel Eye Bream fish before he goes with you. A good spot to get this is on a hidden fishing spot on the map outside The Seaside Cavern. You'll see a little strip of land surrounded by boulders south of the cavern and as you near the water, the fishing icon appears.
When you see the icon, interact to begin fishing. Once you catch the Wheel Eye Bream, go back to Huang in Hishahn and you can invite him to join the party.
After Huang is recruited, you can build a fishing spot at the Drafting Studio. Huang will manage the docks, bringing fish and food into your HQ.