Eiyuden Chronicle: Rising (UP)

Next to where the acting mayor is located is a billboard, sometimes you'll see a side quest on it with the name of the person making the request. The first side quest you may end up getting is to gather some nuts in the Great Forest, they can be something of a rare drop. You just need four of them for the side quest, once you have them talk to Mannon at the gate where you originally entered the town at the start of the game, he should have a blue speech bubble above him. Just let him know you got what he's requested and you'll have completed your first side quest with the achievement popping shortly afterwards.
You can also talk to those with a blue speech without using the billboard, you'll find a few around the town. Two in the Outsider's Lane and Mannon at the gate to begin with. The two in Outsider's lane won't appear until the Blacksmith's has been built.