Before I start off...if you want to see the movie and you don't want to know what happens, please stop reading this blog because it's basically telling you the whole movie. Let me first start off by saying, this was a really good and fun movie to watch. The movie has very strong language and it will generated some controversy for its profanity and bloody violence, particularly from the character Hit-Girl.

The movie tells the story of teenage Dave Lizewski (Aaron Johnson) who sets out to become a real life superhero. Dave is your average kid with growing hormones as he fantasizes of becoming a superhero and making it with his school teacher. After Dave gets his superhero costume through the mail, he sets out to fight crime. Dave then see's 2 thugs trying to steal a car and as he's fighting these would be criminals, he gets stabbed by a knife and then later, ran over by a car.
Dave is then laid up in a hospital and to save embarrassment for trying to stop a crime, he convinces the paramedics to say nothing of his costume and pretends he was brought in naked. In hospital for several weeks he is left with metal holding his bones together which he says makes him look like Wolverine. He has also suffered nerve damage which gives him an above average ability to take a beating. When Dave returns to school, his longtime crush, Katie Deauxma (Lyndsy Fonseca), seems more interested in him. His friends explain she thinks he is gay and wants to take care of him. Lizewski goes along with this in an effort to spend time with her.
The setback didn't stop Dave from being a superhero, and ends up intervening in a gang fight outside a diner. Dressed in costume and using 2 fighting sticks, he fights off the gang. As the fight ends, a man who has been recording the event on his phone, asks Dave who he is, and he replies: "I'm Kick-Ass". The video is posted on the YouTube via the internet and soon becomes an internet phenomenon, making Kick-Ass an overnight sensation.

Dave then sets up a MySpace account so that people can contact him for help. While spending time with Katie, she admits that she was being harassed by a drug dealer, and Lizewski convinces her to ask Kick-Ass for help. He investigates and ends up in an apartment full of violent lowlifes who try to kill him. He is rescued by a costumed, sword-wielding young girl named Hit-Girl (Chloe Grace Moretz), who kills all the attackers and then leaves to join her father, Damon Macready (Nicolas Cage), whose alias is Big Daddy. Hit-Girl (Mindy Macready) jumps across the rooftops and tells Kick-Ass to follow her, but he is afraid to jump, so they leave without him.
Later Kick-Ass is visited at home by Hit-Girl and Big Daddy who have tracked him from his MySpace account. Big Daddy tells Kick-Ass that he changed his IP address so that criminals couldn't find him that easily. Big Daddy also inform Kick-Ass that they can work together.

Meanwhile, local crime syndicate leader Frank D'Amico (Mark Strong) hears of the deaths of many of his men, with many people believing that the new star, Kick-Ass, is responsible. In searching for Kick-Ass, D'Amico kills an impersonator whom he believes is actually Kick-Ass. Running out of ideas, his son, Chris (Christopher Mintz-Plasse) suggests that he set up a new superhero persona ('Red Mist'), enticing Kick-Ass into meeting him. At first, Red Mist attempts to lead Kick-Ass to a warehouse to be killed by D'Amico's men. They arrive to find it on fire, and the men are dead; Red Mist retrieves secret surveillance footage hidden in a teddy bear, which shows that Big Daddy is responsible for the attack. Red Mist asks Kick-Ass to call Hit-Girl and Big Daddy for help, and they arrange to meet at a safe house. As soon as they arrive, Hit-Girl is sitting on a window ledge and Frank D'Amico shoots her, propelling her out of the window and on to the floor below. Kick-Ass and Big Daddy are captured by D'Amico's men and taken to a warehouse where the gangsters stage an internet broadcast, intending to unmask and execute the heroes. After they have been severely beaten and are about to be set on fire, the lights are shot out and Hit-Girl starts a gun battle, killing the villains, but a fire starts and Big Daddy is badly burnt, succumbing to his injuries after a tender moment with his daughter. Kick-Ass tries to convince Hit-Girl to quit, but she is determined not to allow the death of her parents to be in vain and makes one last assault on the headquarters of Frank D'Amico.

Hit-Girl enters D'Amico's headquarters and disposes of several guards by posing as a lost schoolgirl...one of the guards, she actually shoots him through the mouth. On the upper floor, she quickly disposes of the majority of the guards, but runs out of ammunition and is forced to take cover in the kitchen. Not willing to risk a direct confrontation with Hit-Girl, one of the henchmen grabs a bazooka stolen from Big Daddy's safe house earlier and prepares to fire (saying "Say hello to my little friend!"), but is killed by Kick-Ass, who appears riding a jetpack fitted with two Gatling guns (which was purchased by Big Daddy and Hit-Girl earlier in the film). After disposing of them, Kick-Ass and Hit-Girl move into D'Amico's office, and two separate fights ensue between Kick-Ass and Red Mist, and Hit-Girl and Frank D'Amico. While Kick-Ass and Red Mist fight until they knock each other out, Hit-Girl is overwhelmed by the older and stronger D'Amico. As D'Amico is about to shoot Hit-Girl, Kick-Ass appears with the bazooka and blasts D'Amico out the window, where he explodes in mid-air. Red Mist recovers and grabs his father's sword only to discover that Kick-Ass and Hit-Girl are already leaving. They tell each other their names and say goodbye.
Both Hit-Girl and Kick-Ass retire from crime fighting, with Mindy living a normal life and attending the same school as Dave. Upon her first day in school, Mindy is approached by 2 bullies wanting to get her lunch money....Big Mistake as Mindy cracks her knuckles.
Another wave of superheroes have been inspired by his exploits. Red Mist is shown donning a new mask and swearing vengeance, saying "Wait 'til they get a load of me".