noun
half-sister (different father); half-sisters (different father)
Refers specifically to sisters who share the same mother but have different fathers. The term is neutral and factual, used in family or legal contexts.
彼女は私の異父姉妹です。
She is my half-sister (different father).
異父姉妹が二人います。
I have two half-sisters (different father).
Compound of 異父 (いふ, 'different father') and 姉妹 (しまい, 'sisters'). The kanji 異 means 'different', 父 means 'father', and 姉妹 means 'sisters'.