Yes, we did. We could look at Maiden Lane, I, II and III, for starters.

The result is that the private bankers get to assuming that they're going to be bailed out, no matter how egregious their violations.

Same thing will happen here: The bankers/traders that the BOJ/Ministry in Japan select to "manage" some of their FX position will come to assume the access to that money - and they'll lever it up, and then do truly stupid things. 

For capitalism to work, stupidity must be painful.