n 2005, zookeeper Griffin Keyes proposes to his girlfriend Stephanie, but is turned down, citing his career as a zookeeper as the reason, breaking his heart. Five years later in 2010, Griffin is now head zookeeper at the Franklin Park Zoo, caring deeply for the animals. That night, Griffin holds an engagement party there for his brother Dave, but freaks out when he discovers that Stephanie was invited. Dave suggests Griffin come work with him at his car dealership to get Stephanie back, so Griffin considers doing it. The animals hold a meeting that evening as they feel Griffin is the best zookeeper, so they decide to find some way to help him win back Stephanie. Jerome the brown bear suggests they teach Griffin their mating techniques, but Joe the lion protests, reminding them that it's against the animal code to talk to humans. Donald the monkey suggests that they make Griffin look like a hero when Stephanie is at th e zoo tomorrow. The next day, Donald lets Joe out, who confronts Stephanie and Dave's fiancée Robin. Griffin ruins the animals' plan by failing to jump into the lion enclosure, and instead the vet Kate, captures Joe. When he climbs out of the enclosure, Joe accidentally yells at Griffin in frustration, causing Griffin to believe he has gone mad. That night, all the animals break the code of silence and tell Griffin they will teach him to win back Stephanie. He learns their different mating rituals, ending up humiliating himself at a party in front of the other zookeepers and the guests. Griffin then has a talk with Bernie, a forlorn Western lowland gorilla who has spent years in a deep enclosure after allegedly attacking a zookeeper named Shane. Bernie tells Griffin that Shane fell when he was abusing him, but lied, saying that Bernie attacked him. This caused Bernie to mistrust humans. Griffin discovers that Stephanie is dating another ex-boyfriend, a bully named Gal e. Joe's mate Janet tells Griffin that the best way to attract a female is to be seen with another female, so Griffin asks Kate to go with him to Dave and Robin's wedding. In 2012, Griffin successfully grabs Stephanie's attention by first showing off with Kate, then standing up to Gale. Stephanie asks him out to dinner and after they go to a fashion show. Stephanie convinces Griffin to quit his job and he accepts Dave's job offer. This upsets Kate, and also Bernie, who tells him that Griffin quitting proves that he can't trust humans. As he leaves, Griffin warns Shane not to hurt Bernie. Kate decides to leave the zoo and accepts a job in Nairobi. Griffin becomes a star employee at the car dealership but misses working at the zoo. When Stephanie proposes to him, he refuses, dumping her when he realizes that she doesn't truly love him as an individual and that their relationship was all conditional to her. He then goes to the zoo, apologizing to Bernie who he s ees has been beaten by Shane. The animals tell him that Kate is heading to the airport, so Griffin heads out to stop her, stopping at Shane's house first to attack him for hurting Bernie. Then, with Bernie's help, Griffin manages to catch Kate on the bridge and confess his love for her. The two kiss. Six months later, Griffin and Kate get married and are back at the zoo and Bernie is now living in a new enclosure where he gets a great view of the city