YOU SAID:

hi sister that is not actually my sister but i just like to call sister

INTO JAPANESE

こんにちは、妹、それは実際には私の妹ではありませんが、私はただ妹と呼びたいだけです

BACK INTO ENGLISH

Hello sister, that's not actually my sister but I just like to call her sister

INTO JAPANESE

こんにちは、妹、それは実際には私の妹ではありませんが、私は彼女のことを妹と呼びたいだけです

BACK INTO ENGLISH

Hello sister, that's not actually my sister but I just like to call her sister