Wanting to enroll in a language school and go to Japan how hard is it actually.

I am 28 years old and my educational record is not stellar. I recently have found myself with a much higher degree of freedom than I ever have. I want to go to Japan and stay there possibly permanently. My uncle keeps telling me that the immigration procedures are extremely strict in Japan. He is telling me that they will examine every aspect of my life so far and do extensive background checks. Like go door to door in neighborhoods I have lived in previously. Then after that I have to do a 5 hour interview and answer a bunch of questions. I want to go to Japan to study it has been my goal for since I was in middle school. What exactly are the procedures. My plan is to go to a language school and study Japanese then enroll in a Japanese university.