Ted (Josh Radnor) finally mustered up the courage to propose to his girlfriend Stella, who happily agreed, and the two have been immersed in the happiness of engagement since then. Is Stella the woman that Ted has been looking for for many years? Matthew (Jason Segel) has always dreamed of being an environmental protection lawyer, but the distance between dreams and reality is getting farther and farther. In order to support his family, he decided to work for the giant national bank that he once looked down upon. His wife Lily (Alyson Hannigan) did not understand him at first, but later chose to support him. On the other hand, Barney (Neil Patrick Harris), who never gave true feelings to women, found that he actually fell in love with his good friend Robin (Cobie Smulders). With Lily's advice, he launched an offensive against Robin. Robin gradually discovered that he also had a subtle feeling for the playboy Barney.