FBI agent Ma Gang (Martin Lawrence) was recently happy to learn that his stepson Trent (Brandon T. Jackson) had just been admitted to Duke University. However, Trent had no interest in further studies and just wanted to sign a record contract. As a minor, he had no choice but to ask Ma Gang for help. Ma Gang certainly disagreed, and he was busy with an important case. In order to track down a Russian gang member, one of Ma Gang's informants died in the mission, and the memory drive storing important information was also missing. The only clue was that a copy of the drive was hidden in the Georgia School of Art for Girls. On the other hand, Trent, who was unwilling to give up, decided to continue to strive for Ma Gang to sign a contract while he was on the mission. However, an unexpected incident exposed their identities, and Ma Gang had to use his forte again, disguising himself as Shirley's grandmother again, and disguising Trent as his eldest niece. So far, a hilarious and exciting undercover show has been staged... This film is the sequel to the American crime comedy "Undercover Fat Mama".