They are working with Trumpeter. When we get a new Trumpeter 1/700 kit released in the USA, I understand that the same kit is released in a Skywave box in Japan and the Far East. The kits are being developed by the two companies together. In most cases, the results since this collaboration began is that the models are bigger ships than anything (small cruiser and downward) that Skywave used to do alone.
However, there are some odd new subjects being released by Pitroad only - a 1/350 Ukuru class subchaser, and I believe a few odd Japanese seaplane tenders or tankers, that are not distributed very much in USA.
As near as I can track, Pitroad is the label usually used for resin and white metal kits and parts, and Skywave for injected plastic kits.
Most of the "former Skywave" molds that are later released by other companies - Tamiya, DML, etc, have some additional or corrected parts added.
Rick