The Google Translate App is a jaw-dropper.
Just take smartphone in hand, launch the Google Translate App, speak your piece, then press play to let your Japanese acquaintance hear what you said translated into Japanese.
Just like that.
Then, tap once to reverse the languages, and have the Japanese speaker answer your question to play back to you in English.
Works brilliantly, and if the other party is similarly equipped, you can almost have a real-time conversation!
So next time you parachute into Tokyo, your smartphone can translate the way. And it would work in Beijing. Or Seoul. Or Paris. Rome. Berlin. Helsinki. Malta. And even Karnataka.