Ten-year-old girl Xu Nanxing knelt in front of a meat stall on a rainy night, borrowing three hundred yuan to save her younger brother. Zheng Dehai, a butcher, not only lent the money but also took her and her brother home, supporting them for twelve years. She paid back her debts stroke by stroke from her ledger, studying all the way to become the provincial top scorer in science. Along the way, she uncovered the mystery of her identity, fought against the dark operations of the freezer warehouse, won the vegetable market lawsuit, and turned the word "debt" stroke by stroke into "home".