Yamamoto was born in a village in the Kama district () of Fukuoka Prefecture, Japan, on 17 May 1892 (Meiji 25). The village is now part of the city of Iizuka while Kama is part of Kaho District. His father, Tarō Yamamoto, was a riverboat worker on the before becoming a miner in the Chikuhō coalfield. His mother was Shina Yamamoto.
