We arrive in Narita Airport at Terminal 1. We haven't arranged any SIM card for our iPhones and would like to get hold of one at the airport. I've seen people recommending BIC camera stores for relatively cheap SIM cards, and I see that there is a BIC store in Narita Terminal 2. (I also see that there will be one in Terminal 1 opening June 1, but that doesn't help with my trip.)
Would we transfer between the terminals before or after passing through immigration?