The series follows the adventures of 14-year-old Jimmy, a happy-go-lucky teen who makes it his mission to find fun everywhere he goes. This is a challenge because Jimmy lives in Miseryville, the unhappiest town around, run by the megalomaniacal Lucius Heinous the Seventh. Miseryville has one main industry: Misery Inc., purveyors of putrid products guaranteed to cause grief; and they do not come with a money back guarantee. Along with his best friends Heloise (part-time genius, full-time soul-crusher) and Beezy (adventure lover, couch potato, and Jimmy's best friend), Jimmy is determined to surf past all obstacles and bring his infectious enthusiasm to the whole town.
- Miseryville - the town under the control of Lucius Heinous VII. Its purpose is to sustain the lowest quality of life possible. The planet Miseryville is on (and Miseryville may be the entire planet) is shaped like the Miseryville logo, and it has a red sky and three suns. It's inhabitants are mostly monsters except for Jimmy and Heloise who are pretty much the only humans there. Many of the monsters there seems to have French accents, customs, and names (with acception to the occasional Italian accent). Even Heloise's name is French. Lucius's factory over shadows the town. The town is surrounded by tall mountains, grassy meadows, forests, and volcanoes. It seems as though all of the lakes and other places that should contain water contain lava instead but the characters seem to be able to swim in them without burning up (usually). Although it is stated that it has never snowed in Miseryville "Invasion of the Weavils" shows Jimmy going to two different places that have snow and ice. There are screens and cameras that Lucius (and occasionally Samy or Heloise) uses to communicate to Miseryvillians all over town, some hidden in the most random places (such as cakes and trees). Although the town is supposed to be a terrible place to live it does have fun places like theaters, swimming pools, beaches etc. (although they all seem to have some horrible twist). There was once what appeared to be a school in the episode "Scent of a Heinous" during an add for Heinous Perfume, complete with buses, search lights, chain gates, and a total of three girls. It was never shown again.
- Misery Inc. - a huge factory run by Lucius, it resembles a large face. The workers in the factory are always making different products to make people miserable (hence the name). The factory is destroyed in many episodes and it's almost always Jimmy's fault. Heloise has a laboratory there, Lucius has an office that he seems to live in most of the time there, there is a huge "conference room" there, and there are T.V.s and cameras everywhere. Many monsters work there against their will and get no time off, no pay and no benefits from their jobs.
- Clownburg. - A part of Miseryville where the Rodeo Clowns live.
- The Abyss of Nothingness - Seen in a few episodes, it is said to be a vast black hole filled with misery and despair from which no one can escape, although almost everyone who has been thrown into it later appear in different episodes with no explanation of how they got out. Lucius will sometimes try to use it to get rid of Jimmy but him and Samy usually get sent into it by accident (It is never mentioned where it goes or how they get out). On Lucius' birthday it is renamed "The Birthday Abyss of Nothingness" and is shown with a party hat floating over the top.
- Jimmy's House - Seen in many episodes as a simple white house with a red roof, two windows, a lighter red colored door and a hedge going around it. There are also two trees standing beside it. Jimmy's house is right next to Beezy's and Heloise's, and are usually shown in the same scene. Their houses are separated by hedges. Jimmy and Beezy have also been seen playing 'Ultra Target', a game where one catapults himself towards a giant circular board with different colored squares on it. Different 'Bonus Points' have been seen given on account of being Tuesday or Wednesday. It is shown that when chained to the side of the house, Cerbee will sometimes drag Jimmy's house away, usually bringing it back after a few days. Shown in few scenes Jimmy's bedroom is extremely large.
- Beezy's House - Usually shown as a big messy pile of junk inside. In 'The Butley Did It' Beezy hires a butler name 'Butley' to clean it. After doing so, many different treasures are found, such as a skateboard half-pipe and a coffee table. It is also shown that there is a cannon in his house, as he fires himself out of it in one episode. In Bus Driving BFF Chuck describes it as the most dark and disgusting place in Miseryville. Beezy's house is a unique place with its skull-like appearance and horns. Two windows resemble eyes on its gray surface. It looks extremely similar to his father's house.
- Heloise's House - Heloise's house is a tall blue building. It is filled with traps and gadgets that are usually triggered by Jimmy and Beezy. Despite the traps her house is basically normal on the inside. The living room is very large with a fireplace and a couch. Behind a bookcase there is a secret shrine to Jimmy which is opened by a lever sticking out of the wall, although it is shown in Pet Rocky it can be entered through the fireplace. The bedroom is colored blue with a blue bed. Contrary to her personality, there are many girly things about her house, such as a pink computer, flower, star, and heart patterns, and other various decorations. The back yard is filled with tomb stones. There is also a barbecue in the yard, which she uses often.