Buying a mobile phone as a gaijin

I'm going soon to Japan on the working holiday visa for 1 year.

I'm gonna need a keitai denwa, but I know as a gaijin keitais are pretty hard to get, for I heard you need at least a gaikokujin tourokusho and eventually even then they won't sell you one.

Last year I asked a good friend to buy me one. He bought me one and I payed him the fees for it at the end of the month.
As I left Japan he canceled the contract and the keitai was mine (nice souvenir).

But now I will stay for 12 months and I think it will become difficult to find someone that might agree to subscribe a keitai-contract for me. Moreover the paying every month would become inconvenient for me and him/her for I plan to travel a bit through Japan.

Now the question:
What are the possibilities to obtain a mobile phone as a gaijin?
I will need it as fast as possible. I cannot wait some weeks for the gaijin card.

I have a credit card (mastercard). Would it be possible that a Japanese signs the contract but instead of billing him, they bill me through my credit card?

I also heard of prepaid keitais, but I never saw any in usual shops nor keitai stores, only in internet shops. And I don't know the conditions for ordering stuff through the internet in Japan.

any suggestions are appreciated

The easiest way to get a cell phone for you is buying a pre-paid cell phone from J-Phone. Last summer, I went back to Japan for two months, and I needed a cell for myself. In the end, it cost a little more than you subscribe to a phone, but if you limit your out-call and mainly use it as an in-call phone, it works well. Besides, if you need to add more minutes, you need to go to any J-phone shop and pay a particular amount of money for the minutes you would like to buy.
If you have a credit card, it may be possible to subscribe new phone. However, you probably won't be able to constantly use your old phone (to which your friend is a subscriber). Besides, if you have a credit card that has an overseas billing address, it makes things difficult, I assume.

To buy a Pre-paid cell phone, you need to go to the actual "shop" instead of going into the "booth" type of place you see in the department store or other sites. Last summer, J-phone and another company had pre-paid cell phones (not DOCOMO). But I believe J-phone was cheaper back then.

I hope this information will help you a bit. If you need more information, please write under this thread, then I or somebody else may be able to help you.

Thank you for your reply

Last year when I went to Japan, at first I also wanted to buy myself a prepaid phone. I was already informed through the internet that there are some good handsets for cheap prices.

Though the handsets seemed a bit old (compared with subscription cell models), I thought buying a prepaid phone might be more convenient.

I accompanied by a Japanese friend went through thousands of shops, including J-phone shops, conbinis, electro stores, general keitai shops, but none of them had these prepaid keitais. Some even claimed not to know what prepaid keitais are. Note: The J-Phone shop said they don't sell prepaid cells directly but through conbini stores and major electro stores.
We asked dozens of people and we were sent to dozens of shops and finally at the end of the day, in despair of not having found any prepaid cells, my friend bought me one by subscription.

I fear this might happen again.
So maybe I should leave the searching stuff and buy a new cell by subscribing, if possible.