It's no different than when Megaman Battle Network 4, 5, and 6 had Boktai crossovers. Just as Star Force is a continuation of Battle Network, so also is Lunar Knights a continuation of Boktai. Wait, it was taken out, you say? That's why I can't seem to find the crossover. Or maybe you need to do the crossover event with Lunar Knights first and Cross Brother Band with Star Force, despite what the Undersquare guide says. I may have to look into that one...I don't really know how, though, when I'm not in their forum...