I suppose my thoughts about roleplaying most shows I'd watch as a kid or when I was younger, I typically like to respect those stories but do want my RP's to be a bit more mature. (blame my adulthood for disliking most kid things nowadays. :P) You don't really need to make them too dark, if you don't want to. But I do feel most drama is best when it's dark, because more extreme moments will make the tension better. (it can be overblown or done wrong, but it is the most effective method if done correctly.)

I assume when you say this (the darker magical girl shows) wouldn't work as an RP plot, it's because it's blood thirsty and character death is involved. Right? Because a lot of roleplayers are too attached to their character to allow them to face injury or death. Despite I'd argue what makes the great RP's stand out from the good ones, that in the story the characters are involved in, it actually seems threatening and they don't have magical plot armor around them.

But, I do agree that slice of life and fun going adventure rp's are much easier to keep track of and not as demanding. And yes, most magical girl shows have surprisingly complicated plots (and/or good character development.) Which is why people enjoy them. Like I said, I guess I'm in the minority when I do prefer the darker ones. ;3

(forgive me, I typed this late and on a shitty laptop. Because petsitting.)