兄妹 姉弟 姐弟 문자남매
A boy and a girl who have the same parents.
Since it's hard to determine if two characters are brother and sister, it is best to use the tag on named characters known as such.
It is also possible use this tag with either the "brothers" or "sisters" tag or both if there are multiple brothers and/or sisters in the same image.
This tag implicates