Yu Kirino is the NPC created by Akira Oono (Kunai Hakuto) of the series Maou-sama, Retry!. A woman cold like ice, Yu is truly sadistic and cruel who seeks knowledge about the body by cutting and dissecting all that fall into her hands. She got popularity from a number of masochistic players in the game. Yu is a prodigy doctor and a scientist. She has a sadistic personality and the hobby of "clarifying the mysteries of the body", as well as spitting out philosophy, and repeatedly doing many human experiments. Yu surveyed humans scientifically, and all of her documents were meticulously detailed, logging any and all changes and reactions. On the other hand, Yu had no regard for the subtleties of humans nor their hearts, no consideration for the ideals of the privileged nor the mindsets of the meek, and no care for their places in life. She considered it a waste of brain matter to think of such things.

(Source: Maou-sama, Retry! Wiki)