Using Australian phone whilst I am in Japan

This November I will be in Hiroshima for four week..I will be using my Australian phone for calls back to Australia. I have friends inKyoto and Tokyo who will want to call me..but do they need to dial an overseas prefix (Australia is 61)..before they call my mobile number??... even though I am in Japan?...does that make sense?...in other words..what do they dial?...just my number?...thank you

you may call your telecommunication company to use "international roaming service". that will be easiest, but expensive.

Yes, your Japanese friends will need to dial your full Australian phone number including the country prefix. And yes, speak with your provider about rooming before you leave.

For you calling to Australia or Japan just consider if it might not be cheaper to use Skype instead. With Skype you can buy credit and call normal phones or mobile phones at a very cheap rate if you have internet. Essentially when I go to Japan I get a local internet only card and then use Skype to make all type of calls. If my counterpart also uses Skype, Line or WhatsApp we can simply call through that app at no additional cost. If my counterpart (eg my parents) doesn�ft use Skype etc, I can still call them on their landline/mobile phone for a very small fee.
If you need with Skype you can even create your own phone number so that people can call you from their landline/mobile phone.

Have a look if this is something that might be useful for you.

Enjoy your trip to Japan!

Thank you..all clear now!..thank you for your detailed advice.