Evidence-first MVP
How JapanGo reaches a result
JapanGo separates facts we can support from prices, availability, and other market claims we cannot currently verify.
1. Match a reviewed fact set
The service matches the category, item, and priority against a small, maintained catalog. We prefer government, regulator, airline, and manufacturer sources. Each displayed source has a last-checked date; that date is not a guarantee that nothing has changed since.
2. Keep the public result deterministic
The public MVP builds every recommendation and explanation from reviewed rules and fixed translations. It does not call a generative model when you run a check. This keeps the decision boundary auditable and prevents model-added claims.
3. Show uncertainty instead of filling gaps
JapanGo does not fetch live product prices, stock, popularity, reviews, or rankings. When a choice depends on those inputs or the evidence is insufficient, the result should be Compare first, with a manual verification plan rather than a guessed recommendation.
4. Keep arithmetic separate from evidence
The manual calculator uses only values entered in your browser. Its output is arithmetic, not evidence that an item is available or a purchase recommendation.
JapanGo may request a reference exchange rate from Frankfurter using only source and target currency codes. The rate is indicative, can be delayed, and may differ from the rate charged by a card, bank, cash exchange, or retailer. Manually entered prices are not sent to Frankfurter.
5. Treat budgets as editable scenarios
Budget figures are arithmetic scenarios, not observed market prices or forecasts. The daily amounts are visible and editable. Replace them with amounts you have verified for your dates, destinations, and group before relying on the result.
Commercial independence
JapanGo shows no commercial option unless the operator has explicitly approved a current affiliate offer for the page context. When one is active, it is labeled beside the link and is selected independently from the decision, packing, and budget logic. A commercial relationship does not determine the recommendation or create a sponsored ranking.
Important limitation
This method reduces unsupported claims; it does not eliminate errors. JapanGo is not professional advice. Verify consequential details with the retailer, manufacturer, airline, customs office, medical authority, or other responsible source.