Sister, Don't Do This! I Really Can't Spend All My Black Cards

My name is Lin Yu. I was well taken care of by my adoptive parents, but at school, I was just a little transparent person that everyone could ignore. Until that day - a fleet of more than a dozen black Rolls-Royces blocked the school gate. A middle-aged couple who were full of energy rushed over and hugged me and cried: "Son, we have been looking for you for seventeen years..." I was taken home on the spot. The mansion was ridiculously big, and the garage was filled with luxury cars I had never seen before. Black cards were swiped casually. My biological parents who had just recognized me doted on me to no end. What was even more outrageous was that there were more than a dozen sisters from both sides, one more beautiful than the other, one more protective than the other, and one more flirtatious than the other. They said: "We are just your sisters." But you are kissing each other and holding each other high... Sisters, are you serious? Those people in the whole school who looked down upon me were now not even qualified to shine my shoes. By the way, there is also a "Shenhao System" that binds me. The more I spend, the richer I get. So the only worry I have now is: What should I do if I can't spend all the money? What should I do if my sisters are too spoiled? I really just want to be an ordinary rich second generation!