at the beginning, it might be difficult to communicate with a nihonjin (japanese person) in writing, because the language is written in hiragana or katagana, ie. japanese characters. if he writes in romanji, ie. english spellings of the characters, you might not be able to pick much in the long run. anyway what i am trying to say is, a little while after you learn the characters, you can then start communicating constructively. :wink:
you can join the japanese association. they have lots of activities and magazines, etc.
regarding pen pals, i believe by then, you would have met a few of their locals in singapore who would be only too happy to communicate with you, in exchange of you teaching them, perhaps mandarin?