(1) A person who manages affairs on behalf of another without being bound to do so shall conduct that management in the manner most advantageous to the principal according to the nature of such affairs.
(2) If a manager knows or should have known the intention of the principal, he shall conduct the management in conformity with the intention of the principal.
(3) Where a manager administers business affairs in violation of paragraphs (1) and (2), he or she shall be liable to compensate for any damage resulting therefrom even in the absence of negligence; provided, where such administration conforms to the public interest, he or she shall not be liable for compensation unless he or she commits gross negligence.