Experience with marriage in Japan for westerner

Hi, mainly the workload is on your fiance. She has to do paper works in Japan and apply to visa for you. For a working visa, you prepare the application documents with support from your company. However in Spouse visa, Japanese citizen, in your case you fiance, has to get documents of her salary, bank savings, address etc. And she has to write a letter about your relationship such as how you met etc also.
But there might be some changes depends on which prefecture she lives in.
Sorry, it is hard to write every detail because it is a very general question. However, if you can ask about something more specific, I can try to search and reply.