phone WiFi outside of Japan
I'm back in the US for a few weeks, and I'd like to use the WiFi on my phone without using the cell reception. Now, my phone is pretty old, so if I turn on WiFi, it turns on cell reception (but not 3G). If I only use WiFi and don't make or receive any calls or txts (everyone knows I'm out of the country), will I get charged any extra? Can I use the WiFi, with reception turned on but not being actively used (zero bars, anyway), or should I not? I don't want to get back to Japan and find a huge Softbank bill…