Translation guide
In Japanese, the concept of a biological parent is usually expressed by combining the word for parent (親) with modifiers meaning 'real' or 'birth'. The most common and neutral term is 実の親. Other expressions exist but are less common or more formal.
Referring to one's biological mother or father in a neutral way, as opposed to adoptive or step-parents.
He has never met his biological parents.
I am looking for my biological parents.
Literally 'birth parent'. Emphasizes the act of giving birth. Often used when contrasting with adoptive parents or when discussing the birth mother/father specifically. Slightly more emotional or literary than 実の親.
Which is the real parent, the one who gave birth to you or the one who raised you?
A more formal or written abbreviation of 実の親. Used in legal or official contexts, but less common in everyday speech.
Through adoption, the legal relationship with the biological parents is terminated.
Specifically referring to one's biological mother.
The standard way to say 'biological mother'. 母 is the humble form for one's own mother when speaking to others. Use お母さん (おかあさん) when addressing her directly or referring to someone else's mother.
My biological mother passed away when I was little.
Literally 'birth mother'. Similar nuance to 生みの親 but specifically for mother.
Specifically referring to one's biological father.
The standard way to say 'biological father'. 父 is the humble form for one's own father when speaking to others. Use お父さん (おとうさん) when addressing him directly or referring to someone else's father.
I have never spoken with my biological father.
Literally 'birth father'. Less common than 生みの母 but used in similar contexts.
実の親 is the most common and neutral term for biological parents. 生みの親 emphasizes the act of giving birth and is often used in emotional or literary contexts, or when contrasting with 育ての親 (adoptive/foster parents). In everyday conversation, 実の親 is usually the safer choice.
Even biological parents can be abusive.
The parent who raises you is more important than the one who gave birth to you. (proverb)
The English word 'biological' is not directly translated as 生物学的な (seibutsugakuteki na) in this context. While 生物学的な親 is technically understandable, it sounds unnatural and overly scientific. Stick to 実の or 生みの.
His birth mother put him up for adoption.
I don't even know my birth father's face.