using an old handset

Hello, I've literally checked like 200 posts here about using/getting mobile phones in Japan, but didn't find the answer to my question, so I decided to ask directly.
I have and old handset of my friend from docomo (SH03A) which now I'm using in UK (so its probably unlocked? calls and sms works perfectly, no internet/email). I will be going to Japan for my year abroad soon and I wonder if there's any chance of getting this phone to work again? I highly doubt that the number registered to the phone is still active, I had it for 2 years now.
I've read that docomo is not doing pre-paid service any more, but I wonder if anyone tried using different service providers on docomo phones? I also wonder if this is possible how does it affect internet? (after two years of using this phone I'm dying to finally use this lovely browser and other functions!) Or are there some other options?

Look into a b-mobile prepaid sim card. They have very affordable monthly plans that should work with your phone:

http://www.bmobile.ne.jp/index.html

Thank you for the response.

I think this would work, but I would loose an i-mode applications.
Do you know if they do pre-paid sim crads as well? I'm going only for one year, so I cannot take a contract.

You would lose imode if you are not useing Docomo service. There is a chance that your docomo handset might qualify for one of docomo's value plans, which I believe are month to month, non-contract plans.

Here's a list of applicable handsets:

http://www.nttdocomo.co.jp/charge/purchase/compatible_model/index.html

And more info on the value plan:

http://www.nttdocomo.co.jp/english/charge/bill_plan/plan/value/index.h...

I'm not positive that out of contract phones are eligible for these plans, however, so you may need to contact Docomo directly to find out.

yllwsmrf, thank you so much, it is very helpful!!