In Edge City, Stanley Ipkiss, an insecure cartoon-loving bank clerk, is frequently ridiculed by everyone around him except for his co-worker and best friend, Charlie Schumaker. Meanwhile, gangster Dorian Tyrell, owner of the Coco Bongo nightclub, plots to overthrow his superior, Niko. One day, Tyrell sends his dazzling singer girlfriend, Tina Carlyle, into the bank to record its layout in preparation for a robbery. Stanley is attracted to Tina, and she seems to reciprocate. Unable to enter the Coco Bongo to watch Tina perform and after his faulty loaner car breaks down while driving home, Stanley looks over the harbor bridge in despair, lost in thought of what to do. His stream of thought is interrupted, however, when he finds a strange wooden mask near the harbor. Upon returning to his apartment and wearing the mask, he is transformed into a mischievous green-faced figure known as "The Mask", who is able to cartoonishly alter himself and his surroundings at will. With his newfound confidence and lack of inhibitions, Stanley indulges in a comical rampage through the city, humiliating several of his tormentors, including his temperamental landlady, Agnes Peenman, and the mechanics who gave him the faulty car. The next morning, Stanley encounters detective Lieutenant Mitch Kellaway and newspaper reporter Peggy Brandt, both of whom are investigating the Mask's activity. To obtain the funds necessary to attend Tina's performance, Stanley again dons the mask and raids the bank, inadvertently foiling Tyrell's robbery in the process. At the Coco Bongo, Stanley becomes infatuated with Tina to the point that he cartoonishly drops his jaw and pops his eyes out at the same time, then showing his beating his heart out of his chest literally and finally turns his head into that of an Tex Avery cartoon wolf, which he bangs his head to get it back to normal and the two share a kiss after an exuberant dance sequence. Shortly after, following a confrontation with Tyrell for disrupting the robbery and stealing his girlfriend, Stanley flees, leaving behind a scrap of cloth from his suit, which turns back into a piece of his pajamas. Tyrell and his henchmen are then arrested by Kellaway. Kellaway finds the piece of cloth and suspects Stanley to be the perpetrator. The next day, Stanley consults Doctor Arthur Neuman, a psychiatrist who has recently published a book on masks and deduces that the mask is a creation of Loki. It is also revealed that the mask's powers are only active during the night. Later that night, Stanley meets Tina at a local park as the Mask, which initially disturbs her at first, along with being too strong and wild towards her, but he manages to win her over with his charm and sweet nature to the point they are about to kiss until they are interrupted by Kellaway, who attempts to capture him. Stanley flees with Peggy after he manages to distract the police with a mass performance of the titular song from Cuban Pete; she then betrays him to Tyrell, who was released due to insufficient evidence connecting him or his henchmen to the robbery, for a fifty thousand dollar bounty. Tyrell dons the mask, becoming a bulky and malevolent green-faced being. Tyrell's henchmen force Stanley to reveal the location of the stolen money, before turning him in to the police.