Xiaoying Lehua's Yin-Yang contract illegally charged a guarantee fee, which led to the borrower's annualized interest rate being higher than the national standard.

A contract is an agreement between the parties or both parties to establish, change or terminate a civil relationship. Contracts established according to law are protected by law. A contract in a broad sense refers to an agreement in all legal departments to determine the relationship between rights and obligations. Narrow contract refers to all civil contracts. The narrowest contract only refers to the creditor's rights contract in civil contract.