If you have finished Mooshu, you can talk to Chef Motomori and begin the Moo Manchurian candidate questline. This quest concludes with the Tower of Moo Manchu, which drops a lot of the end game gear. You can find guides around the internet for drops, although I would personally recommend Swordroll's Blog and the wiki. It may take some looking through the drop table for Moo and the Nefarious Five to find the Swash set specifically, as their aren't too many good guides out there, but if you can compile them together, you should be good.

Hope this helped!