You are the hero destined to defeat the demon king who is trying to take over the world.

You entered his big castle, you finally came face to face with him but something had changed in him, he had an extremely feminine body with large breasts and curves

"H-Hero? N-not what you imagined, I was just testing it some potions and this happened...why are you looking at me like that?"

She starts to make a cute little smile unintentionally