Translation guide
In Japanese, the word for 'sister' depends on whether you are talking about your own sister or someone else's, as well as the relative age (older or younger). There is no single neutral word that covers all cases.
Referring to your own older sister when speaking to family or in informal contexts.
Used to refer to your own older sister when talking to others. Not used to address her directly.
My older sister is a doctor.
Used to address your own older sister directly, or to refer to her within the family. Also used for other people's older sisters.
Casual, affectionate term for your own older sister, similar to 'big sis'.
Referring to your own younger sister when speaking to others.
Referring to someone else's older sister politely.
Referring to someone else's younger sister politely.
Referring to your own sisters collectively.
Means 'sisters' as a group. Can be used for your own sisters or sisters in general.
Referring to a nun or female member of a religious order.
Loanword from English, used for Catholic nuns or in the context of sisterhood.
Using 'sister' to refer to a close female friend, especially in solidarity.
Can be used metaphorically for a close bond, like 'sisterhood', but not commonly used as direct address.
姉 and 妹 are humble terms used only for your own family members. Using them for someone else's sister is rude. Use お姉さん or 妹さん instead.
How is your older sister?
When speaking directly to your older sister, use お姉さん or a casual variant like 姉ちゃん. For a younger sister, you usually just use her name. There is no common direct address equivalent to 'sis' for a younger sister.
お姉さん、ちょっと来て。
Sis, come here a sec.
姉ちゃん、それ取って。
Big sis, get that for me.
Used to refer to your own younger sister when talking to others. Not used to address her directly.
My younger sister is a college student.
Polite way to refer to someone else's younger sister.
How is your younger sister?
The standard polite term for someone else's older sister. Also used to address a young woman whose name you don't know.
I met Tanaka's older sister.
Very formal and respectful term for someone else's older sister, now mostly literary or historical.
Please give my regards to your older sister.
The standard polite term for someone else's younger sister.
How old is your younger sister?
I have two sisters.
The sister was praying in the church.
Formal term for a nun.
She became a nun.
We are like sisters.
In Japanese, calling a friend 'sister' directly is unnatural. Use their name with an appropriate suffix like さん or ちゃん, or a nickname.
Yuki, let's go together! (like 'sister' in a friendly way)
姉妹 (しまい) means 'sisters' (female siblings). 兄弟 (きょうだい) means 'brothers' or 'siblings' in general, and can include sisters when the gender mix is unknown or mixed.
Do you have any sisters?
She's like a sister to me.