As of 2003, the village has an estimated population of 3,086 and a density of 25.98 persons per km², with a total area of 118.78 km². Nanmoku, like many rural areas in Japan, is seeing a significant amount of population decline; in 1955 there were more than 10,000 inhabitants. The majority of the remaining villagers are over 60 years in age (56% in 2000)
The village is particularly famous for hitoboshi (火とぼし), the two-day local fire festival, the largest in the prefecture Many people who have moved away but still have family in the village return for this festival, and it is popular with tourists as well. Though such fire festivals were once popular, few remain. Nanmoku's version falls on August 14th and 15th, and coincides with Obon, a festival honoring dead ancestors. However, Hitoboshi itself commemorates the village's victorious alliance with the Takeda during the Sengoku period During the festival, villagers take turns standing on a bridge and twirling burning bales of hay over the edge.