I feel that Americans tend to use the term "friend" a lot more casually than, say, the Japanese. In Japan, your boss is never your friend. Neither is your teachers, colleagues, parents or siblings. A "friend" in Japan is somewhat closer to a soulmate, and not surprisingly we don't have many (for some people, not at all).
If the Japanese word you are thinking about translates better to soulmate than to friend, then why not just assume it means soulmate instead of friend.
Surely Japanese people have relationships that fall between soulmate and coworker/acquaintance.
I often say that I think the greatest stroke of genius that Facebook had was calling it 'Friending' and 'Unfriending' instead of 'Add to your contacts' and 'Remove from your contacts'.
Then you're still friends. Depending on your performance and how both of you treat each other, that friendship may become affected but as long as you still treat each other as friends and hang out, that friendship will continue.
