I don't think I'd be able to think of any advice like that for learning English, so I'll be interested if a native Japanese person is able to do it for their birth language.
My advice would be something like: be born into a family of native speakers; hear and see only that language; speak, write, and think in only ever that language; progress through school as a child where you're surrounded by only that language being taught and used; ...
Hopefully you'll get something a bit more useful than this though. :D
October 3, 2016 at 12:47am