NIS America have confirmed to Siliconera that Mugen Souls Z's bath mini-game will be the only cut content when the JRPG makes its way to western PS3s next year. The mini-game was cut from the previous Mugen Souls localisation as well and from a Youtube video, seems to involve placing bananas and other fruits on semi-naked young looking girls.
In the Japanese version of the game, the mini-game is required to receive some stat increases, while in the western release you'll receive those stat increases for free once the mini-game would normally be unlocked.
If you fancy checking out what the cut content is, Youtube user Lenne Valkyrie seems to have documented the mini-game here. While it doesn't technically feature explicit nudity, it isn't safe for most places. Be warned.
Mugen Souls Z will be coming to the PS3 sometime next year in America and Europe.