They're native to Japan, Philippines, Palau, Indonesia, and the Ryuku Islands.
I believe these fish tend to show up in the early spring as they often enter shallower waters in the winter, esp. near cold water upwellings.
IME, these fish didn't do well in a group. They were fine for months, then picked each other off with a vengeance (we now have a single specimen that is doing very well and is a couple of years in our possession).