I'm less worried about names of places, that's not really where my interest lies. I like story. :)

So usually in these games there's a thing with a Harvest Goddess having to be restored. We could always go that route. I have a couple ideas I can throw out there:

1- What if there were five relics hidden around the island they had to find, and then they had to restore the relics to a shrine at the center of the island?
2- What if there were a beast somewhere on the island that was damaging property and endangering lives, and it needs to be tracked and stopped?
3 - What if a company from the city were trying to buy out the farms and small businesses and they had to work together to keep the economy strong so they don't have to sell?