Ted (Josh Radnor) and Robin (Cobie Smulders) have been together after many twists and turns, but they broke up because Robin was afraid of getting married. Because of the end of this relationship, Ted resumed his bachelor life, and Robin went to Argentina to relax. However, when Robin returned to New York, she brought back a handsome boyfriend, Kay, which hit Ted hard. Playboy Barney (Neil Patrick Harris) is keen on finding beautiful girls to develop one-night stands. He is very excited about Ted's return to being single, and he instigates Ted to become his "best partner" again. When will Ted meet his true love? After marriage, Matthew (Jason Segel) and Lily (Alyson Hannigan) decided to move out of the apartment they shared with Ted. The two used up their savings to buy a new house, but found that the house was crooked. Although their lives occasionally have some bumps and bruises, the couple generally live a very happy and fulfilling life.