Theiamillis Gre Fortorthe

A princess who came from another planet, where she is a member of the nobility of the Fortorthe Empire. Her choice for picking Koutarou's room was merely random, however as part of her trial to her empire's throne she has to make any occupants in that randomly picked area to swear loyalty to her, which much to her chagrin, didn't end up well and even found herself violated (accidentally) by Koutarou.

She has a habit of using the first person personal pronoun 'Warewawa" or "Wagawawa" which is often used by Japanese belonging to the nobility in reference to one's self. She and Koutarou are often at odds, she also thinks highly of herself that she refers to Koutarou as "Neanderthal"; however, Koutarou also calls her "Tulip" in reference to Sanae's move when she is flipped her long skirt to put her in an embarrassing restrained. She is in the company of her servant, Ruth, who serves as her companion and adviser.

The dress she wore also serves as her malfunction tool that she calls "Blue Knight" which can also transform into a weapon.

(Source: Anime+)