YOU SAID:
jimmy is my true sibling
INTO JAPANESE
ジミーは私の真の兄弟
BACK INTO ENGLISH
Jimmy is my true brother
INTO JAPANESE
ジミーは私の本当の兄弟
BACK INTO ENGLISH
Jimmy is my real brother.
INTO JAPANESE
ジミーは、私の実の兄です。
BACK INTO ENGLISH
Jimmy is my real brother.
That didn't even make that much sense in English.