Living in a culture from which an art form comes will always give one
a better grasp of it than one can get anywhere else. You can, for example,
begin to see how the shape of the mountains, and how the land meets the
ocean finds its expression in those rock arrangements.
But there are many, many skills about garden
design that are truly more efficiently learned at workshops in your area.
"Going to the source" is not always the best answer.
If you are committed to going to the source, JOJG has some leads on internships
with Japanese landscapers. Try to keep your expectations in line, though,
with the fact that most Japanese
landscapers spend years learning the skills
that you are interested in...passing extremely detailed tests (e.g., on
how many centimeters high a basin should be compared to the bamboo fence
behind it), and then waiting for the right customer to come along to be
able to employ those techniques. Don't be in too much of a hurry, and be
grateful for what does come your way.