ML Isn't Super Rich

Orphan + disaster survivor paying off a debt to loan sharks by working a variety of rough, temporary jobs.

The ML's parents are not wealthy but are well off. However, they cut him off when he changed his major to music. The ML has recently graduated and is setting out to become an idol / musician. 

ML is an aerospace engineer / researcher. He forewent a hefty salary as an investment banker to pursue his passion for space exploration despite the lower compensation.

The ML grew up in an orphanage and works as a senior assistant in a craft brewery. He lives in a very sparse rooftop apartment. He is smart and capable. He knows how to charm and manipulate people and when he sets his mind to something he's reckless enough to go all the way / do anything necessary to see it through to the end. So he's very capable of earning lots of money if he ever wanted to, but he's not materialistic and doesn't care about money. On occasions when he does receive huge sums, he doesn't hold on to it for long.

Student athlete (swimming major) who grew up in the care of his middle-class aunt and uncle.

The ML's father is wealthy enough to own a house in the city (where the ML stays for most of the drama while looking after his nephew, who is in high school, while his sister is out of the country) and on Jeju island where he is enjoying retirement; however, due to an accident that happened when the ML was 17, he became very distant and difficult to interact with;  the ML studied abroad (art) in Germany in high school and university and chose to work at a small company where his classmate is the CEO that designs stages for musical performances; he is not looking to advance at work and is not materialistic; he owns almost nothing beyond his car, his clothes, and his dog. 

High school boy raised by a single mom who had him when she was young.

Orphaned high school student taken in by local kind-hearted laundromat owner. He fills in for his brother who is a director at a large company.

Although he would be rich if he had lived with his birth parents, he instead grew up under the care of a man who saved his life as a baby on a small island. They were not struggling to eat but they lived a very simple country life.

The ML is an orphaned slave who flees Joseon for America to escape the reach of his former master. In America, he joins the marines and through his valour in battle he achieves the rank of Captain. He is posted to Joseon as acting consul of the US legation. This means that he has power, good pay (especially because he is paid in US dollars), and the army pays for some of his expenses. However, if he were to leave the army he would have only a small handful of belongings to his name and no accumulated wealth. 

Commoner doctor who can't spend any money he makes from secretly (illegally) treating nobles.

ML is a student who goes to university on an athletic scholarship. Not super poor. Not super wealthy.

Exterminator / MMA fighter in training.

Manager of an airline check-in team.

ML's father is a cop. His mum splits and marries a rich man. Eventually he becomes a dentist.

ML is an office worker. He was adopted by a well-off family, but they favour their biological daughter. The daughter uses him for money, rather than the family giving him money.

The ML becomes an orphan and spends several years in jail. He's never poor because he receives a substantial insurance payment, but he invests all of it and saves all the money he makes while working after his release from prison, so he mostly lives very thriftily. 

The ML's mother died when he was young and his father remarried and moved abroad. He was mainly raised by his older sister and the family of his older sister's best friend (the FL). He works as an artist for an international gaming company, and worked in the US for three years. He doesn't struggle with money, but he's not rich either.

Team leader at a marketing company.

ML temporarily takes over ownership of a coffee shop from a friend. When it burns down, he lives with the FL (his childhood friend) so he can use the money he would've used for rent to rebuild the shop. 

ML is a semi-successful artist (paintings and drawings). He lives in a house he inherited from his parents and drives a car left behind by his now-married sister, so he lives very comfortably, but he's not rich-rich.

The ML's father marries three times; none of his parents or step mothers have much money; he lives in small towns; he's smart enough to get scholarships and to live within his means, so he never has an issue with debts, but he is never wealthy; after his father is sent to prison, he lives with his step mother who runs a small restaurant until he attends the police academy; when his father tries to share the profits of his book with the ML, he refuses 

ML works as a hotel assessor for a travel company. He doesn't kiss up to or get along with his boss so he hasn't been promoted despite his talents.

High School student. Lives with his grandmother above her small restaurant. 

ML is cut off from his middle class family. He has a senior position (but isn't the CEO) at a tech start up. He had to take out a large loan in order to buy his apartment, and is very focused on paying off his debt. 

ML lives with his mum who does odd writing jobs like writing CVs.

Poor student from the countryside.

Orphan supported by FL's family.

ML is an internationally acclaimed dancer who eventually decides to also study choreography so he can make money. He is estranged from his family.

Golden hearted con-artist - completely poor + obsessed with making money.

ML is a struggling musician with a boring office day job

Takes jobs to fight ghosts because he needs the money for an operation that will take away his ability to see ghosts. 

Both of the male leads are high school students who live with their single fathers. One father does hard labour and the son dreams of becoming a successful athlete to lift his father's burden. The other is financially well off but is not acknowledged publicly by his father, who sees him as a mistake and a reminder of his failed marriage. 

ML is an orphan raised by his farmer grandfather in the countryside. He moves to Tokyo after his grandfather is scammed and forced to sell his field so that he can earn enough money to buy the land back. He works as a mover.

Adopted + forced to pretend to be stupid by circumstances. He lets his adoptive niece go to university in his place as the family can only afford to send one of them. He works as a taxi driver and then applies to become a reporter. 

ML works as part of the passenger assistance team at Incheon International Airport. We don't know much about his parents / family, but they don't appear to be rich. The ML was in a serious accident as a young man and was able to afford a wheel chair. It's unclear whether or not he worked for the next 11 years or where his money came from. He did attend a good university and got top marks. Unclear whether he had a scholarship or not. He lives in one of the residences that many of the airport employees live in. 

Child of single mother working in another city / living on his own. He hopes to get a scholarship to medical school.

ML is a normal high school student who likes sports more than school work. He grew up living next door to the FL in a town outside of Seoul. 

ML works at an aquarium and then as a policeman

Abandoned by his parents and looses his adoptive parents. He's essentially penniless. 

An ex-cop who leaves the force to run his own undercover operation for personal reasons.

Conned by his landlord while trying to get a cheap place to live. His parents died when he was in elementary school and he lives off minimal support from his older brother.

The ML is an orphan and successful gambler. There are times when he lives well after a big win, but generally his fortune is short lived. The FL on the other hand is the sole heir of a large fashion group.

Deputy Manager.

The ML is a piano tuner.

Food delivery guy.

Raised in poverty as an orphan in the countryside.

ML starts out working at a non-central weather forecast calculating station (he's a weather forecaster in the sense that he makes the forecast  - he doesn't present the forecast on TV). He moves to the head office but still has a junior position.

ML works for the emperor. Not sure exactly what his status is, but he seems more like a high level servant or soldier than a wealthy noble or a prince.

Works at a major corporate law firm, but isn't a lawyer. He's a staff member on the litigation team and shares an apartment with a colleague.

In most timelines the ML becomes a rich idol, but he doesn't grow up rich / isn't rich for part of the time that he interacts with the FL