Transcoding SJIS HTTP post parameters

Hello all.

I am in a bit of an unusual situation and was wondering if anyone has done this before and have any tips.

I am using rails as a web-app and an API. I have been told that the API needs to accept HTTP Post requests with SJIS (A Japanese text encoding) parameters instead of UTF-8.

Since I have no experience with this (Need to do some testing) I was wondering if anyone could offer some advice / gotchas (Need to see how rails processes parameters and if it mangles them in any way if not UTF-8)

On a sidenote. SJIS contains some funny characters which usually get mangled when converted to UTF-8. Can anyone speak up for the effectiveness of ruby's transcoding abilities?