Very cool! Thank you for showing this. I'm from the UK so I don't speak Japanese (sorry if you have to use a translator), but I am obsessed with this sort of thing. You deserve more love <33
After applying your change, there will have two keys not working ( \ and ¥ ). But those two keys can be reactivated by the HHKB Remapping Tool! Also, the ~ ` key in the US layout is missing. I re-mapped the key on the upper right corner into the HHKB key (in US mode, it works as ~ ` key). The other one, I just use it for an extra shift key.