That reminds me: In the Mario & Luigi games, there are usually lots of interesting characters who don't appear in other Mario games, but this time it seemed to be mostly main-line characters. Was this also something to do with it being a crossover?
Otani: Oh no, nothing to do with that! This time, since we had so many paper characters and doubles of the same character together, we had to prioritize moving the story forward and communicating the contrast between them. It would have been really difficult to put in original characters and work out when would be the best time for them to appear.