@Bacaww, Marie Rose is pretty much the exact opposite of an ojou-sama. She's a maid, she doesn't come from a wealthy or noble family and she behaves childish and unrefined. The stereotypical ojou-sama of DOA is Helena and to a certain point also Kokoro.
wouldn't nyotengu be classed as ojou-sama to some extent, too? but she'll never replace helena as best ojou-sama, doesn't matter how much nyo grows on me.