Beca, a freshman at Barden University, is cajoled into joining The Bellas, her school's all-girls singing group. Injecting some much needed energy into their repertoire, The Bellas take on their male rivals in a campus competition.

Mac and Kelly are trying to sell their home with the arrival of another baby. A couple, Eric and Jessica Baiers are looking to buy; the realtor tells Mac and Kelly that their house is in escrow for 30 days. Meanwhile, Mac's friend, Jimmy, and his once-again wife Paula are also expecting a baby. At the Phi Lambda sorority, Shelby, a freshman, learns that sororities are not allowed to host parties, and can only attend frat parties. Shelby goes to a frat party and meets two other freshmen, Beth and Nora. They are disgusted by the sexist and perverse nature of the party and leave. Bonding over their dissatisfaction, the trio decides to set up a new sorority, Kappa Nu, to host their own parties.