As Chris implies, we Westeners often have a need to formalize these things. Titles like this are used in context and will change depending on who you are talking to and about.
Indeed. Hierarchy and in-group/out-group relationships are a fundamental part of the Japanese language. They are not a fundamental part of the English language, and so we non-Japanese-fluent English speakers can confuse ourselves and others if we just translate the words without understanding the relationships.