Japan SIM rental question

Emergency numbers should be toll free. Helplines may cost money, but most have toll free or collect numbers as well. See these pages for more info:

http://www.japan-guide.com/e/e2229.html
http://www.japan-guide.com/forum/quereadisplay.html?0+99405

Alright. Say, I was thinking of that about calling ambulnace etc... Since I only know some basic Japanese and will bring a phraselist it might be a barrier calling an ambulance. Is it possible the phone operator might know some English?

Do not go for softbank sim rental. Its a rip off if you turn on your cellular data. 1mb cost 15USD which is the max charge a day.

15 USD?! Oh gosh, are you serious?

The roaming rate is 5-6 USD / mb.

By the way, is it possible to use only Wifi connection when on a hotel that has free wifi, so that the phone does not search for paid data connections anywhere outside the hotel?

Do not go for softbank sim rental. Its a rip off if you turn on your cellular data. 1mb cost 15USD which is the max charge a day.

I think you are misunderstanding how the softbank (iphone) rental sim works. The actual charges are more like 30 USD per mb, BUT it maxes out at 1500 yen per day. In other words, with that sim you essentially have the option to get unlimited data at a charge of 1500 yen per day. That cost is right on par with other mobile unlimited data services, but there are cheaper options if you shop around. The softbank sim is explained here:

http://www.softbank-rental.jp/e/rental-plan-ib03.php

By the way, is it possible to use only Wifi connection when on a hotel that has free wifi, so that the phone does not search for paid data connections anywhere outside the hotel?

Yes, on your phone turn off cellular data and turn on wifi. Another way is to turn on airplane mode and then turn wifi back on.