I have good news and bad news. The good news is that the Senran Kagura: Estival Versus crossover costumes for Dead or Alive Xtreme 3 have been released.
The bad news, is that Koei Tecmo did not treat them like their usual periodic costume release, which can be purchased with in-game currency if you don’t want to pay real money. They’re all paid DLC pretty much like their equivalents for Dead or Alive 5: Last Round.
If you have the Asian version with English subtitles, you can find the set with nine costumes here. The cost is HK$196, which translates to a fairly expensive $25 for the whole set.
Costumes are also available separately, priced at HK$29 each, which is a bit south of $4.
If you want to see whether they’re worth the investment or not, you can check out the screenshots below.