Peter Klaven is a successful real estate agent in Los Angeles who is about to take a big step in his life: he is going to marry his girlfriend, a charming and understanding woman named Zooey. However, there’s a small problem: Peter has no close friends. As he prepares for the big day, he realizes that he has no one to invite as his "best man" at the ceremony. After a series of disastrous interactions with acquaintances and old coworkers, Peter decides to go on a quest for a new best friend, which turns out to be a more complicated challenge than he imagined.
Through comedic dates and awkward moments, Peter meets Sydney Fife, a laid-back and outgoing guy who seems to be everything Peter is not. Although their personalities clash at first, the two quickly establish a unique and fun connection, leading them to share unusual experiences and lessons about friendship and life. However, the relationship between Peter and Sydney begins to complicate when Zooey starts feeling jealous of the growing friendship between them.
The film is a hilarious comedy about the modern man's search for male friendship, as he navigates romantic relationships and the challenges of adulthood. On his journey, Peter will discover that friendship can be just as important as love, and that sometimes, a new best friend can change everything.