Sang-ung is a public servant living in Seoul. He’s a regular guy, dreaming of becoming a homeowner and marrying his partner, like many others in their mid-30s in the city.

Sang-ung considers himself somewhat selfish, with little interest in helping others. He’s saving to marry and has no intention of using the money for anyone else. But his ordinary life takes an extraordinary turn when he’s bestowed with superpowers: As long as he has cash on him, he can use unimaginable strength and resilience.

The problem? His unexpected abilities only work when he spends money — and there are far too many people and dire situations in the world that could benefit from his help. Can Sang-ung hold on to the unremarkable life he’s always dreamed of, or will he find himself using his extraordinary powers for the sake of others?

“I could relate to the feeling of money slipping away with every breath,” Lee tells Tudum. “My character constantly struggles with the question of whether, when saving others, the decision comes from his own will or from someone else’s. I’d say we’re alike in that I can’t bring myself to turn away when I see someone in need of help.”

The Red Sleeve

Min-suk has been Sang-ung’s girlfriend for nine years. The 32-year-old is the head of accounting at a midsize corporation and, naturally, also manages Sang-ung’s income and spending as a hobby. She keeps a close eye on every detail of his finances. Practical and frugal by nature, she strongly dislikes anything inefficient and lavish.

Though she sees Sang-ung’s superpowers as wasteful and often tells him not to dip into their savings, part of her can’t help but feel supportive of his attempts to protect others. While her boyfriend is off playing hero, Min-suk tries to manage their wedding preparations on her own, but her plans are constantly derailed by dangerous threats.

Kim Hye-jun says she sees a lot of herself in her character. “Like her, I’m a realist who thinks a lot about efficiency. I found her unconditional support and encouragement for Sang-ung especially endearing because it goes beyond those rules,” she says. “When it comes to the people I love, those rules of efficiency tend to fall apart. I think that’s true for all of us — for example, with family, where efficiency kind of loses its meaning.”

A Shop for Killers

Byeon Ho-in is a lawyer — and fittingly, his name translates to lawyer in Korean. He also serves as the representative of the Korean Association of Superhumans. Whenever he drinks alcohol, he gains superpowers like phasing through solid objects. Unlike Sang-ung, whose powers cost money, Ho-in pays with his own health.

Kim calls Ho-in’s sense of responsibility for the common good “admirable,” but it comes at a major sacrifice. “My first thought was whether I could do the same myself,” Kim says. “I’m not very good at drinking, so I’m not sure I’d even know how to handle it all. I probably would have wanted to avoid [the power] somehow — maybe find a way to pass it on or figure out how not to take it on myself.”

As the leader of the association, Ho-in tries to bring superhumans who operate in the shadows out into the open, hoping they’ll use their abilities to fight for the greater good. But now he’s one of the last two remaining members of the organization, as the others have sold their powers to a crime syndicate and vanished without a trace.

Descendants of the Sun

Bang Eun-mi, who goes by Bread-mi, works at a convenience store while also serving as a member of the Korean Association of Superhumans. She can use telekinesis when she consumes calories. Bread-mi usually fuels her superpowers with bread, but occasionally she indulges in candy or other sweet, calorie-packed treats.

Bread-mi has a quick temper, especially when confronted with injustice, which often prompts Ho-in to remind her to rein in her anger. “She’s at an age when appearance matters most, yet in an unstable line of work, she can’t eat or diet properly, constantly investing her energy in others,” Kim says of her character. “I believe that led to an underlying sense of anger within her. Even so, I think her dedication to continuing her work reflects her inherently good nature.”

Working alongside Ho-in, Bread-mi remains committed to pursuing justice without selling her powers, though she understands why some of her peers long to surrender their abilities and return to normal life.

The Queen’s Classroom, Along with the Gods

Jo Anna is the heiress of Beominhoe, which means “The Mundane Vanguard.” The organization operates in the shadows, backed by the Beomha Group, a conglomerate with extensive connections across politics, business, and other sectors. Anna believes that, in modern society, power matters more than a superpower.

Anna has power, wealth, and influence — but lacks both a superpower and a conscience. Armed with the nefarious group’s extensive resources, she hunts superhumans. She’s also behind the development of illegal drugs that replicate the superhumans’ unique abilities — all to gain her father’s trust and protect her position as heiress.

From the moment she first read the Cashero script, Kang felt confident she could bring an emotional complexity to the villain. “Growing up without hardships, [Anna] is headstrong and unpredictable. She may have inherited wealth from her father, but she lacked his love and is fiercely competitive to protect her position,” Kang says. “The villains also have their flaws, which I think makes them even more compelling.”

My Roommate Is a Gumiho

Jo Nathan is Anna’s younger brother, though they aren’t close like many ordinary siblings — they’re archrivals. Both want to succeed their father as the leader of the group. Summoned home from the United States by their father, Nathan is even more ruthless than his sister and obsessed with claiming Sang-ung’s powers for himself.

Nathan is a man of relentless ambition, willing to cross any line to achieve his goals. Guided solely by pride and self-interest, he possesses a chilling duality: he’s capable of profound kindness one moment and ruthless cruelty the next. He emerges as the most formidable threat, not only to the superhumans, but even to his own sister.

Lee shares that this is the first time he’s played a villain. He approached the role with a clear focus on the idea of “the hunt” — meaning Nathan’s drive to steal superpowers. “My character is someone who will stop at nothing once he sets his sights on a target,” Lee says. “When acting the role, I tried to immerse myself in those ‘hunting’ moments and perform as if his smile genuinely comes from enjoyment.”

Crushology 101