Looking through some old Alarums & Excrusions zines, I found the following in a comment I wrote back in May 2002:
Actually, I’ve got some ideas about running a Ranma-like game, and they require some different mechanics. […] At the core is a token mechanic, where each character has disads that he can trigger (or that can be triggered by other characters). Triggering your own disads gains you a token (I’d probably use poker chips) in the GM agrees that your PC was actually disadvantaged, or it was funny. Triggering someone else’s disad requires you to give that player a token. Some special powers might also require paying a token to use for advantage. This mechanic simulates the stupidity of the Ranma characters — they often fail to do simple, rational things because they lack the tokens to pay for them.
I could swear I saw a martial-arts Wheel of Fate game out there somewhere on the web a few weeks ago, but Google hasn’t found it for me.