Mahou Shoujo Madoka★Magica

Synopsis

Mami and Kyubey explain to Madoka and Sayaka that Kyubey has the power to grant wishes, but in exchange, those who make wishes must become magical girls to fight witches, who are born from curses. Mami offers to take Madoka and Sayaka with her on a witch hunt to help each decide if there were a wish they would risk their lives for. The next day, Kyubey, who cannot be seen by normal people, accompanies Madoka and Sayaka to school, where they learn to communicate with each other telepathically. Homura visits Madoka once again to repeat her warning, and refuses to answer when Madoka asks what her wish was. After school, Madoka, Sayaka and Mami follow the aura of the witch from the previous day to an abandoned building, where they manage to save a woman controlled by a witch from committing suicide. They then enter a portal inside the building where Mami finds and defeats the witch responsible, earning a Grief Seed which can be used to recover magical power. (Source: Wikipedia)