So maybe you saw on Matt's blog, but I took a stab at making my own Japanese curry the other night:

I feel like everything went okay until the simmering part. I thought I had enough water until I suddenly had more of a paste than a gravy at the end. (I had only filled the water up enough so that everything was just peeking out; next time I'll have to remember to really drown everything.) Also, the curry roux just never seemed strong enough, every time I tasted it the curry flavor was missing, so I ended up using about 3 blocks of roux. I added a little honey towards the end and was sort of impressed by how much of a difference it actually made, taste-wise. I made beef curry using beef cubes for stew. I sauteed the beef first, but after all the simmering it got a little dried out. Not sure how to avoid that part for next time.
I know we don't have many Japanese curry fans around but if anyone makes any kind of curry themselves, how do you make it?