Business as Unusual

One member of our rascally group of oddballs inherits (or has had a lifelong dream of running) a certain type of business -- something our rascally group is completely inappropriate doing. Maybe it's a biker gang that suddenly has to serve as the fire department, or the strippers run a gas station, or a group of teenagers try to run a ship, laundromat, or house-painting company. Needless to say, Hilarity Ensues.

One common variation has the villains taking over the business in order to ambush the heroes or evade capture. The key is that they do so poorly, and usually for laughs.

When used as one arc of a longer narrative, it often gives way to a Montage. Also a good opportunity to demonstrate the team bonding.

Subtrope of Fish Out of Water.

Anime & Manga

 * During the first season of Pokémon, Giovanni leaves Jessie and James in charge of the Viridian City Gym while he goes out. It ends about as well as you'd expect.

Comic Books

 * The Beagle Boys at least once have run a front operation that was more successful than their planned heist.

Film

 * Tom Hanks' character in Big
 * Gas Pump Girls
 * Malibu Bikini Shop
 * Revenge of the Nerds has a long montage when the boys of Lambda Lambda Lambda renovate their new frat house.
 * Thunder Road
 * Tommy Boy

Live-Action Television

 * One episode of Arrested Development has Lindsay take over the business for a day, over the course of which the business literally falls apart.
 * Dharma and Greg once broke into a small-town diner to use their phone, but when caught by the police, claimed to be relatives of the owners there to run it while they were away. One thing leads to another, and at closing time, they ended up with quite a bit of money in the till for the owners (despite "Ike's" wooden leg).
 * Frasier and Niles take over a restaurant-- and their father later recounts it as the craziest blunder they ever make.
 * On How I Met Your Mother, Ted and Barney convinced the owner of McLaren's not to close early and let them lock up. They open the bar for a couple of hotties they had been trying to hook up earlier and a few of their friends... the entire Arizona Tech marching band. Oh, and they break a few glasses imitating Tom Cruise in Cocktail.
 * Laverne and Shirley: Lenny inherits his uncle's diner ("Laslo's Place"), which he & Squiggy decide to rename ("Dead Laslo's Place") and run themselves, hiring Laverne to be the cook and Shirley as the waitress.
 * Lucille Ball is a prime example of this.
 * As are The Three Stooges

Theater

 * Played at in Sam Sheppard's True West

Western Animation
"Moe: ... and if anyone wants potato chips or anything fancy, tell him to go to Hell. Homer: Can do. Now, don't you worry about a thing. gleefully turns on a beer tap, spilling the beer onto the floor Moe: shuts off the tap Hey, what are you doing? I gotta pay for that! Homer: No, Moe, you've got it all wrong. People buy beer from you. Moe isn't confident the bar is in good hands, but he leaves anyway. Before he gets two steps away, there's a huge explosion. When Moe rushes back in, Homer looks at him nonchalantly and says, "I thought you had to go.""
 * Kim Possible: Dr Drakken once owned a muffin company. It was more successful than the original evil plan. But he recognised the success and was going to cancel the original plan.
 * The Simpsons:
 * "The Mook, The Chef, The Wife, and Her Homer"
 * "Homer the Moe": Moe goes off for a few days leaving Homer in charge of the bar.