(!) Contains headcanon.

Spoilers!!

"For all the happiness you wish for someone, someone else is cursed with the same misery. That's how it works for magical girls, and that's how it works for me. I was stupid, so stupid..."

Sayaka Miki (美樹さやか, Miki Sayaka) is one of the five main Magical Girls in the anime and manga series Puella Magi Madoka☆Magica. She is a student at Mitakihara Middle School and is in the same class as Madoka and Homura. She sometimes calls herself the Magical Girl of Justice (正義の魔法少女, Seigi no Mahou Shoujo).

Source: https://madoka.fandom.com/wiki/Sayaka_Miki