The Immortal Loan

In 3026, the only currency of humanity is lifespan. Brain-computer interfaces connect to consciousness, and the system deducts 'interest' from memories monthly—this is called the 'Immortal Loan.' The contract, hundreds of thousands of words long, states in the smallest print: interest always outpaces production, and the principal can never be repaid. The day you default, first your memories are erased, then the face of your loved one, and finally your personality. There won't even be a death record; you 'never existed.' Seventeen-year-old Li Xiuping carries two unpaid debts: one is his own, and the other is for his sister, Lin Xiaolu, whom he 'bought.' The infant girl, found in the snow on a stormy night by his mother and less than a hundred days old, doesn't even have an account in the system—she is an 'illegal existence' that can be erased at any moment. When the reclamation program reaches the deepest part of his consciousness, the system halts. There lies a line of code from a thousand years ago, a 'death message' from the founder of the Immortal Loan. The system's only loophole is now in the hands of a teenager. From then on, some want to take his mind, some want his life, and others want to take the two people he would die to protect: a sister found in the snow who ties her life to his, and Shiyu, who saved them both but hides her warmth behind coldness. For the first time in a millennium, someone can 'repay' the Immortal Loan. But what needs to be repaid has never been just the debt. — Description from novelcodex.org