Does anyone know how to self learn an accent, since the accent I want to learn is a rare Japanese accent that sounds totally beautiful.

It's not even the general dialect, but from some island in Japan. It's called Amami, and it's proven to relax people in electroencephalograms.

Interesting! I just googled learn accents free and got some interesting stuff. I will now work on a British dialect... something I've been wanting to do! Maybe a google search on learn japanese dialects free will turn something up for you.