The first reason that Peony did believe that stuff about 'other worlds' was the whole thing about no one knowing he was the emperor here - and if they did, they were really good at pretending. When people started talking about not even knowing what fonons were, that was the second reason.

The third reason? It was just more fun that way. Cute alien girls? Hello.

Peony was about to congratulate the blonde when he heard faint sounds of a battle happening at the top of the stairs, and moved in front of Cyrille, trusty mop at hand. Turning back to the girls with his shine-tube, he whispered, "Hey, there's something up there. Do we want to try to sneak past or help whoever it is?"

Truthfully, Peony would be happy either way. Acting like a hero could probably be fun, especially if he got to save a cute girl - but sneaking past a battle could be just as fun, providing they didn't get caught.