Im also heading out to Japan in about two weeks. I was planning on getting a pay as you go phone since Im going to be there for around 4 monthsI'm assuming that you will be on a visa other than a tourist visa since you will be staying 4 months.
but I have an Iphone and am wondering if it would just be cheaper to get the pay as you go sim...
I believe that prepaid sims are no longer available. Softbank used to sell them but someone mentioned on another thread that they were canceling the service. Also, there seems to be no mention of prepaid sims on their website anymore.
http://mb.softbank.jp/en/products/
You could use your iphone with a rental sim (assuming your phone is unlocked) although it would be expensive and I believe that it doesn't include a data plan making it essentially pointless.
I think a prepaid phone would be your best option. I've used softbank prepaids and the service is good. They start at around 5000 yen for the handset and credit is available in 3000 and 5000 yen increments. Some softbank branches will sell a prepaid to you with just your passport, but others may not, and it will be easiest if you have your alien registration card when you apply.
