Have you ever bought Perpaid Sim card in Japan?
Please tell me merit and demerit.
I bought the sonet SIM at Narita for around 4500yen and ended up wasting my money as it didn't work with my phone Samsung GalaxyS5. My friend's iphone worked so we used her phone to check the map and etc. Better check the compatibility before you buy.
I bought Bmobile SIM before.
My device is iPhone 5.
Bmobile delivered the hotel I stayed.
I bought Bmobile sim around 4000 yen for 14 days.
there many pre-paid sim service now.
other service are reasonable price now.
I bought a SIM at Narita too, forgot the company name. It was definitely convenient to have internet connection with me for translation, maps, and train search. I recommend you get one.
I got one from Yodobashi camera in Akihabara. The staff asked us many questions when we buy it, wished they could just let us try with our device. At the end it worked. Yea, definitely worth getting one. Many locals can't communicate in English.
There are many threads on this topic on tripadvisor forums.