Two very different series are about to join forces in Senran Nin Nin Ninja Taisen Neptune: Shoujo-tachi no Kyouen, which—as you might have gathered from a few key words in the title—brings the worlds of Senran Kagura and Hyperdimension Neptunia together.
You can also see some gameplay starting at the 2:37:59 mark below, followed by comments from Miku Itou at the 2:43:06 mark.
Characters from both series will appear in the Game Ninja World along with a new Miku Itou-voiced protagonist named Yuuki.