Question: do uk mobiles work in japan?
Answer: Your iPhone and Galaxy will work in Japan on DoCoMo and Softbank networks, as they are 3G/4G. Roaming charges for UK phones are extremely high, like £1.20-£1.50 per min to call out and to receive. Activate overseas roaming plan before leaving UK. Just dial like +44 7976 123456 to call another UK number.