Oh dear, it seems like the visa process is a massive pain in the arse.
A bit unnecessarily complicated.
I have to be invited in an official document, but I also have to travel with my wife who has to jump through extra hoops because of this. She has to get her original birth certificate for Edogawa and submit forms in Japan and in the Japanese embassy in the UK. I really hope these restrictions are lifted a little bit before I have to go. We will have to have to start getting ready a couple of months in advance just because of the post.