Email from Japanese Prepaid Phone to US Phone

I am moving to Japan and would like to get a cell phone in order to stay in contact with my friends in the US. I have read about the prepaid phones in Japan, where you buy the phone and pay 3000 yen a month to use? Plus 300 yen for unlimited emails per month? So are these unlimited emails good to the US? Can I send an email to my friend's US iPhone or will that cost extra? I understand that texts are not very common in Japan, but would this apply to texting as well? I hope my questions made sense. Thank you in advanced for any replies!

Emails to PC addresses are classed differently to Japanese phone email addresses.

The cheap unlimited emails is probably just to other Japanese phone's email addresses, but they may have a package that covers all email.

what the OP mentioned is Softbank 3G prepaid service.

and yes, 300yen per month for unlimited email PC or mobile email.

Initial purchase (mobile & sim with credit charge) will cost from as little as 5,+++yen to over 1+,+++ yen. It depend on the mobile model.

Credit recharge either 3,000yen or 5,000yen and either charge last 60 days. remaining credit after 60 days will be gone unless recharge before 60 days, which the balance credit is accumulated.

http://www.softbank.jp/en/mobile/price_plan/prepaid/

Thanks so much for the replies!

So the unlimited PC mail can be to any email address, regardless of country? I've tried looking on Softbank's site and can't seem to find info on international mailing. Sorry, I'm still new to this! Thanks!

S!Mail is the mailing systems that
uses e-mail addresses to exchange messages with SoftBank handsets (including iPhone), non-SoftBank handsets, PCs, etc

SMS is only between softbank phone

PDF English guide for Softbank 3G Prepaid
http://cdn.softbank.jp/en/mobile/set/data/service/prepaid/shared/servi...

Emails to PC addresses are classed differently to Japanese phone email addresses.
The cheap unlimited emails is probably just to other Japanese phone's email addresses, but they may have a package that covers all email.

For the user perspective there is virtually no difference between sending to a PC or a phone address. Softbank prepaid (and all the Japanese service providers) cover all email communication in their unlimited mail plans. There isn't such a thing as international e-mailing, and you can use their service to keep in touch with you friends/family abroad without any extra fees.