Weijie (played by Li Chongrui), Abao (played by Lu Kaijun) and Jianren (played by Hong Cijian) are "bad kids" in the eyes of three adults. They don't study hard and think of all kinds of strange ideas in their heads all day long. Due to years of neglect, the rebellious Jianren went astray. He was heavily in debt and had no choice but to seek help from a loan shark company. In order to help Jianren, Weijie, who is good at mechanical manufacturing, invented a "debt collection machine". With the help of the debt collection machine, Jianren can do things as if he has God's help. The gangster Lao Ma (played by Eric Moo) accidentally saw the power of the debt collection machine. With evil intentions, he tried every means to get the debt collection machine and use it in the drug smuggling business. Teacher CK (played by Daniel Chan) noticed this conspiracy. He was kind and righteous and decided to help the three children and lead them back on track.