Farmers, fishermen, and craftsmen.
There are no walls around the Heimin District. The fields and rice paddies that surround the city would be a minor obstacle, at best, to an invader. Most of the doshin who patrol The Merchant District live here and can be counted on to look after their neighbors if there's trouble.
Most of the province's distilleries and breweries are located on the outskirts of the district, close to the fields. Craftsmen of every stripe can be found here and the carpenters are of especially high quality. The city's blacksmiths are also found here, including several who are entitled to craft samurai weapons.
Buildings range from poor, but sturdy fishermen's huts along both banks of the river to large, well-made peasant houses for the better craftsmen and respected families of doshin.
The district will flood in severe weather. This doesn't happen even yearly, but it happens often enough for all to remember and fear it.