Re: Dangan Ronpa and Housepets! Crossover?
There's no issue with doing a murder mystery, though you are right, Dangan Ronpa is rather violent (from my brief wiki foray). But really, it's not quite so much violence as it is graphic detail that's the main issue we care about.
So the story is certainly welcome here, but violent/gruesome scenes would need to maintain a sense overview rather than detail. More of a "tell, don't show" rather than the usual story-writing advice
And always remember, if you are not sure how well individual chapters or passages fit our guidelines, send a PM my (or any other mod's) way, and we'll advise as necessary