Three friends transform into superheroes at night when they put on their pajamas. During the school day a problem arises, and during the night the culprit is found by the PJ Masks and the problem gets solved by sharing ideas, recognizing strengths and weaknesses, and the ability of working together to get the problem solved. Everything is made right for the children the next day thanks to the PJ Masks. Because bedtime is the right time to fight crime.
PJ Masks follows three 6-year-olds, Connor, Amaya, and Greg, who lead relatively normal lives by day, where they are neighbours, classmates, and friends. However, at night, they become Catboy, Owlette, and Gekko, and fight crime as the PJ Masks, a superhero team. Together they go on adventures, defeat criminals, solve mysteries, and learn valuable lessons.