Shimenosuke was born as a legitimate child of Iyo no Kami (Governor of Iyo Province), Ienori TERANISHI, who was a Shinto priest in Sunari Village, Ama County, Owari Province (currently Aichi Prefecture).
尾張国（現在の愛知県）海部郡須成村の神職、寺西伊予守家班の嫡子として生まれる。