Way to go!
The overhead is minimal, if you do it right, but I like your idea too, it's more pro
It doesn't really matter where you incorporate, the taxes are virtually the same, I looked into that too. I'm keeping it SP until I hit the 10mil a year on profit and then going KK, that way I optimize tax savings and have no restrictions on employee status, other than 1 full time Japanese citizen.
I like to remember that nothing is as hard as I thought it would've been after I try to do it.