When an official with the National Tax Agency, the Regional Taxation Bureau, or the Tax Office examines the details of the gross revenue and necessary expenses prescribed in the preceding two paragraphs as they pertain to the income taxes of a person subject to the provisions of those paragraphs, the official is to inspect the books referred to in paragraph (1) or the documents referred to in the preceding paragraph; provided, however, that this does not apply if there are circumstances that make it difficult to inspect the books or documents.