The day the true heiress, lost since childhood, was brought back to the mansion, everyone expected a classic tale of "the cuckoo in the nest." Hana, the adopted daughter, was the flawless jewel of the household. She gently took her sister's hand and whispered softly: "Don't be afraid, I'll take care of you from now on." Yet behind closed doors, she methodically pushed this sister into one carefully constructed trap after another. The parents, blinded by favoritism, only had eyes for the child who made the most noise. Mio, the true heiress, struggled in despair, withering away. Until Tsukiyo, the perpetually silent elder sister, finally extended her hand. "No more tears," she said. "From this moment on, I'll teach you—how to reclaim everything that belongs to us, with interest."