What the name of this manga

So I've thinking of this manga but I can't find it anywhere, so the fl get reincarnated in the body of an empress who is madly inlove with the Emperor but the Emperor hates her also he as a concubine, the fl as red hair ans in one of the episodes where concubine is supposed to explain something from her planet(she came from Earth) the empress come in with a red dress with a slit, I really like this manga but I totally forgot the name of it