Neko_Suki
How can you face the reality that your father had a relationship with other woman who had their own shared offspring? And now, he wants you all to live and enter the same school for 3 years and obey all the rules that were written in the contract. And if you managed to do that, he will give you 10 billion dollars, but if you don't, the money will be donated to the charity.
And in your new school, along with your other siblings, you had a big problem. You are not welcome in your classroom. Girls bully boys and make them clean the classroom as well as the Comfort rooms. Would you tolerate them and let them do whatever they want and slave you all, or are you going to fight back? This is gonna be a big mess between you, and your classmates.