True, but that was medical and humanitarian support. It did not involve combat troops. If that changed in any way, I hadn't heard about it.
Just deployment of medical arms of their military has stirred up plenty of controversy. The general idea appears to be as follows: "The last time Japan deployed troops outside its own borders, they did unbelievably terrible inhumane things. Japan should be banned from deploying its military until further notice." <-- That would be the idea up to 2004. The fact that the deployment of military medical personale raised such a stink internationally, it is clear that many in the world still don't trust Japan to behave themselves.
IMHO, the shadows of World War II are old and dead. Events over 60 years in the past should not keep Japan from being able to deploy combat military outside of its borders, but it has yet to happen. It may still be against the Japanese Constitution, but I don't tend to do a really great job of keeping up with Japanese politics.