The movie begins in the world of monsters, where a young monster named Michael Mike Wazowski, who visits Monstors Inc., Monstropolis company, which is the most profitable scaring company and he is extremely motivated and determined to become a scarier monster when he grow up. After eleven years, Mike joins a scare monster university and he meets another monster named Sully and the two become good friends.
Mike concentrates on his studies and he is determined to become a scarier monster while Sully, belonging to the family of very talented Scarers begins to falter as he is too confident that he is blessed with the ability of being a scarier monster. But unfortunately the two fights and break the scream can of Dean, Abigail Hardscrabble, which angers her and she fails both of them stating that Mike cannot scare people and he is not scary enough while Sully did not study nicely.