Read the quotation correctly
A hypothetical change from 140 to 150 yen per US dollar means a dollar buys more yen: the yen has weakened against the dollar. Those numbers are illustrative, not today’s exchange rate. Reversing the quotation changes how the movement looks without changing the underlying exchange.
Trace the exposure
A Japanese importer paying a fixed dollar invoice needs more yen after that change. A business receiving dollar revenue can receive more yen when converted, before considering costs and hedging. A visitor with dollars experiences yet another perspective. There is no single winner or loser for the whole economy.
Do not confuse a mechanism with a forecast
Interest-rate differences, expectations and trade flows may matter, but a single factor is not a reliable prediction rule. Contracts, pass-through and hedging can change how a currency movement reaches particular households or firms.
Use dated data
Bank of Japan statistics provide exchange-rate information; quote the series and date if discussing a real movement. Separate a bilateral rate from an effective rate across trading partners. The first question is always: which currency, which quotation and whose exposure?