The theme is fully compatible with pal consoles I am from the uk myself.
To be safe make sure priiloader does work and if yes your all set.
If you are worried about making the csm files yourself I suggest using wiithemer.org it will make the csm...
A lot of the older themes only change the us and eu health screens
Its quite an easy fix I'll do it later today
1773348728
I've fixed this now so if you would like to redownload it it should work fine on a Japanese Wii