Coal Mining and the Tomoko System
Large-scale coal mining began in Kushiro in 1916, and the area’s Pacific Coal Mine became one of Japan’s largest. Mining was arduous manual labor that involved chipping away at coal seams deep underground in the light of carbide lamps, which used acetylene gas.
Miners organized themselves into work teams called tomoko (“friendship groups”), each headed by a senior miner in a supervising role. New miners generally spent three years as apprentices before they could join a tomoko. These groups started before unions were established in Japan but served a similar role, facilitating the sharing of skills and encouraging support among members. The miners in a tomoko pooled their money to help each other in the event of injury, disaster, or mine closure, and to contribute to the cost of events like weddings and funerals.
New members were inducted in a formal ceremony in which they drank sake with other members from a shared cup as a symbol of unity. The names and addresses of tomoko members were written on paper scrolls. These lists provide insight into the patterns of migration to Kushiro. The tomoko system was gradually phased out with advances in mechanization and social security, which was introduced at the mine in 1930.
