Mahou Shoujo Madoka Magica

There exist familiars who have the power to grant one wish to a chosen girl. However, in return that girl must then become a magical girl and fight against witches, evil creatures born from curses that are responsible for murders and suicides. A schoolgirl named Madoka Kaname and her friend Sayaka Miki are approached by a familiar named Kyubey and a magical girl named Mami Tomoe with offers of becoming magical girls. Another mysterious magical girl named Homura Akemi tries to prevent Madoka from agreeing to the contract.