How Could a Little Cake Be a Villain?

I woke up one day and found I had become a magical girl.

What? Magical girls are destined to die?

Fortunately, that has nothing to do with me.

Wait, what did you say? To save the other magical girls, I have to defeat them and force them to sign an unfair contract?

Well, that's what they say...

"Don't run away, cutie! Big Sis has candy at home!"

"Susu, why are you so soft?"

Isn't something backwards here?

"Wait, listen to me! I'm actually the witch who defeated you and forced you to sign contracts!"

The girls looked at one another, then spoke in unison:

"How could Susu possibly be the big bad?"

"Huh?"