Masujiro was born as the eldest son between a rural physician, Takamasu MURATA, and his wife Mume, in Suzenji Village Aza Omura, Yoshiki District, Suo Province (present-day Suzenji, Yamaguchi City, Yamaguchi Prefecture.)
周防国吉敷郡鋳銭司村（すぜんじ）字大村（現・山口県山口市鋳銭司）に村医の村田孝益と妻むめの長男として生まれる。