A Golden Companion

A golden companion is a friend so incredibly close to you that at first you see them as pseudo-siblings, and then as time goes on, even more than that, to the point where they aren't a pseudo-sibling, but a golden companion. These people are the closest of the closest to you and will stay with you until the end of time. A Golden Companion is never a romantic one, a Golden Companion that is romantic is called a Rose-Golden Companion.