Small and medium-sized companies often need a market answer before they can fund a large research project. This makes the order of sources important. A broad report can guide attention, but it cannot answer every product, channel, tax, standards, or partner question. A source stack moves from orientation to a decision-specific test.
Layer one: official orientation
Use an official overview to define the relationship and the available programs. The European Commission’s EU trade relations with Japan page gives a route into the agreement and related cooperation. JETRO’s Investing in Japan report gives a current route into inward-investment conditions and trends.
Orientation sources help identify terms and institutions. They do not prove product demand. Store each useful statement with its date, scope, and direct link so later work does not depend on a remembered summary.
Layer two: rule and classification
Translate the business question into a classification question. What is the product or service? Which legal entity will sell it? Which market is the destination? Which channel will be used? A rule search without these fields can return correct but irrelevant guidance.
Use the applicable official agreement chapter, authority page, or statistical classification. If the text is available in several languages, keep the original-language title and the language used for analysis. Record whether a page is guidance or the controlling instrument.
Layer three: market evidence
Choose indicators that match the entry hypothesis. Import value can show recorded trade, but it does not show addressable demand for a specific offer. Investment stock can show a long-term position, but it does not measure the number of suitable distributors. A company count can help with channel sizing, but it needs a defined industry and geography.
Write one sentence for each indicator: “This measure can support…” and “This measure cannot prove…”. That small discipline limits accidental overclaiming.
Layer four: validation plan
End the desk research with a short list of facts that need direct validation. Examples include buyer requirements, partner capacity, implementation cost, local support needs, and realistic sales timing. Name the person or organization that can validate each fact and record the result separately from the public-source research.
The Japan Ministry of Foreign Affairs economic-relations page can help confirm the official policy frame, but it cannot validate a company’s unit economics. Keep policy, market signal, and company evidence in their proper layers.
A good source stack does not make the decision automatically. It reduces uncertainty in a visible order. It shows which conclusions come from primary public evidence, which are analytical inferences, and which still require a customer, partner, regulator, or adviser to confirm them.