Ryouko Uchida is a quantum researcher for the Magic Circle Project. Initially, her research involves a lot of chasing after quickly-disappearing phenomena and seems fruitless, but after she and Kyouji meet the Dragon Cavalry, she discovers that the Magic Circle Project, if successfully activated, would annihilate all of existence. She is then determined to stop it at all costs. She initially is irritated by Kouriyama's attitude and occasional sexually-charged jokes. But apparently, she grows to find him attractive, and in the final episode, she rushes to embrace him after he is shot. (Source: Wikipedia, edited)