Cinderella? Not while I'm here!

After accidentally discovering the secret hiding place of her older sister, the little girl suffered a great shock that will greatly affect her current and future life.

—I will protect my sister! And I won't let anyone touch the big brother!

Knowledge is power, and money moves the world!

Born in a noble family, money is not a problem, the knowledge you want can be acquired just by asking.
Loving parents, a perfect brother and a lovely sister; Calling her the little princess in her family wouldn't be wrong.

However one day suddenly a completely unknown child appeared.

Too bright... Is this child supposed to live with us?

—You... look like a doll.

Eh? What? What the hell was that?