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 joke. But apparently she grows to find him attractive, and in the final episode she rushes to embrace him after he is shot.

(Source: Wikipedia)