No Talking on Train (車内での通話禁止 - Shūnai no tsūwa)
The strict custom of not talking on your voice phone inside Japanese train cabins. Passengers highly value a quiet, stress-free commuting environment, viewing telephone conversations as disruptive and intrusive.
Rooted in Japan's civic value of 'Meiwaku' (not inconveniencing others). While whispering to a seatmate is tolerated, speaking on a phone introduces loud, one-sided conversations that disturb the peace of closed spaces.
If you receive a voice call while on a subway, do not answer it, or immediately hang up. If on a Shinkansen bullet train, stand up and walk to the deck area between carriages before answering the call.
What is the smartest, non-disruptive response if your phone rings inside a train cabin?