Hi Daniel,
I am a fellow kiwi who has been based in Osaka for a few years. I do Shorinji Kempo, which is very well represented here in Osaka in terms of places to train and level of teaching. Of course I might be a bit biased, but my recommendtion is to give this a try. It is not a koryu martial art, but has a number of similarities to Aikido.
Where did you train in NZ by the way? What kind of Aikido did you learn?
Regards,
Justin