Omura Mencia was born in 1600. She was the fifth daughter of Sumitada Omura, Lord of Hizen (Nagasaki Prefecture).
Under her father's inﬂuence, she was baptized and received the name of Mencia.
Married at the age of 16 and gave birth to Takanobu and Nobutatsu. She was a wife of Hisanobu Matsuura, eldest son of Shizunobu. Although the Matsuura family was anti-Christian and persecuted Christians, she persuaded her husband to have their sons baptized.