As far as I know, there are various problems due to migration. I am surprised to hear that there are many parts that are not fulfilling in Japan though.
So, I found a site that is a general migration method, so I wanted to introduce it.
1. Qualification for foreigners to stay in Japan
(1) Status of residence for employment activities
(2) Status of residence for purposes other than employment activities
(3) Status of Residence based on status or status
2. How to move to Japan by marriage
(1) Case of marrying a Japanese spouse
(2) Procedure to welcome foreign spouse