'1.5 times the effort for 3 billion cells': The four cast members of 'Yumi's Cells' who beat 1,200-to-1 odds

A small light bulb that had been dark all along suddenly flashes. Every time a "good feeling" strikes, the bulb above Intuition Cell's head lights up. Emotional Cell looks as though he might burst into tears at any moment, one hand pressed to his waist. Sneaky Cell flaunts his presence with heavy-lidded eyes and a languid air, while Etiquette Cell stands beside him, clicking her tongue and never losing the dignity of a proper "Confucian girl." Diet Cell spins hula hoops in a flurry, while Wash Cell nags her to please, for once, take a shower.

Tiny cells crowd together in a charming little village. When 3 billion cells unfold before the audience in a sweeping visual spectacle, the theater becomes a "virtual space" cut off from reality — a fantasy playing out entirely inside one person's head. A webtoon that racked up 3.4 billion views has come alive on stage. The stars here are neither Yumi nor her boyfriend Ku-woong, but quite literally "Yumi's Cells" (running through Aug. 23 at Seoul Arts Center).

The Korea Herald met the four performers most responsible for bringing Cell Village to life: Han Jun-yong, 37, who went from playing Angel in "Kinky Boots" to becoming Yumi's Emotional Cell; Yeon Ji-hyeon, 27, who plays both Writer Cell and Miser Cell; Lee Gyeong-uk, 41, the scene-stealing Sneaky Cell; and Kim Yeong-ung, 25, the Intuition Cell who fought through staggering competition to earn his place on stage.

All four perform in a single cast, taking the stage every day. They were unanimous: "This show is a performance that every actor builds together."

Actors are not made overnight. A great deal of unseen work goes into reaching the stage, and it all begins with the audition process.

"I think it's the same for every ensemble actor. You scour the internet and social media to see if any audition notices have gone up, and when one does, you apply for all of them. It's a profession where you have to be chosen," said Lee Gyeong-uk.

The production had been in planning and script development for five years before its premiere, and word had already spread widely among musical theater actors. When auditions were held last November to find the show's unsung heroes, virtually every musical actor in South Korea showed up. The competition was fierce. Kim Yeong-ung recalled that the audition for Intuition Cell alone drew 1,200 applicants for every one spot.

The preparation process was just as intense as the odds. Unlike conventional auditions that assign set songs and choreography, this production gave candidates a "free choice" mission to showcase their individual talents — a challenge that sent everyone into deep deliberation. Yeon Ji-hyeon's flair exploded right there in the audition room. She chose "8282" by Davichi, saying she played up the feeling of "call me right now, give me that acceptance call." Han Jun-yong, who plays Emotional Cell, laughed at her story: "So that's why they called you so fast."

Because roles had not been assigned in advance, the actors had no idea which cell they would end up playing. Lee Gyeong-uk laughed as he recalled getting his acceptance call: "We talked for a long time about the schedule, and then I suddenly thought, 'Wait' — so I asked, 'By the way, what role am I playing?' That's how I found out I was Sneaky Cell." His castmates piled on with their own reactions. Yeon Ji-hyeon said she was stunned when she first saw Lee after the casting announcement: "I thought, 'Wow, that is a perfect fit.'" Lee responded that he actually enjoys being sneaky by nature, adding that his goal is to deliver adult-rated comedy in the vein of veteran entertainer Shin Dong-yeop — provocative but never off-putting.

Yeon Ji-hyeon had originally been cast as Anxiety Cell, but her tap-dancing skills — honed during her time in "42nd Street" on Broadway — earned her a dual role: Writer Cell, who serves as Yumi's alter ego, and Miser Cell. She had not worn tap shoes in six years, so she began taking private tap lessons a full month before rehearsals started. "At first I was just scrambling to keep the beat," she said, "but now I'm tapping out the sound of Yumi typing — the feel of her writing."

Kim Yeong-ung, the youngest of the four and a "Kinky Boots" alumnus, said he broke down in tears — "close to wailing" — when he received his acceptance call for Intuition Cell 30 minutes before a regional curtain. Han Jun-yong, meanwhile, was cast as Emotional Cell almost by accident: during his second-round audition he was reading lines for Rational Cell when he suddenly erupted in fury, and the creative team promptly designated him "Super Emotional" instead. Having already shown his irrepressible energy in "Kinky Boots," Han has fully inhabited Emotional Cell this time around — though he admitted that if the show is remounted, his ambition is clear: "I'd absolutely want to play Sneaky Cell."

"Can I call you Baekgu?" (a line by Sneaky Cell in "Yumi's Cells")

"Yumi's Cells" was different from the start. Unlike licensed productions where actors perform a given script as written, this original premiere gave the cast both greater freedom and greater pain. Until the show reached the stage, every actor was simultaneously a writer and a director, and the rehearsal room became a space of constant collaborative creation, with ideas flying at every turn.

The original webtoon and drama series unfold from Yumi's perspective, but the musical rewrites the story from the cells' point of view. Aside from Yumi (played by Tiffany Young and Kim Ye-won), Love Cell (Kim So-hyang and Yu Ria) and Trainee Cell 109 (Choi Jae-rim and Jeong Taek-un) — a character original to the musical — each cell arrived without a clearly defined character. That is why the actors threw themselves into building their roles from scratch, so that, as Lee Gyeong-uk put it, "each cell could exist as its own character and draw the audience in."

Sneaky Cell is a wellspring of ideas. In the "Sneaky Party" scene, Lee Gyeong-uk turns the stage upside down in a burst of concentrated chaos. Trainee Cell was originally designated 109 after Yumi's birthday — Jan. 9 — but Sneaky Cell renames him "Baekgu," a common dog's name. A dog's bark leads to the line "There are no bad dogs in this world," and the joke goes that the first character in "trainee" (견습, gyeonseup) doubles as the character for "dog" (견). All of it came from Lee's own imagination.

"I remember being told to just throw everything out there, even things I thought might not work," he said. "When those pieces come together one by one, they create a powerful force. This was a show that involved an unusually large amount of watching and refining each other's ideas."

Some of the show's best moments grew out of mistakes turned into ad-libs. In Sneaky Cell's entrance during the "Sneaky Party" scene, a performance bit involving the tearing away of long trousers gives the otherwise whimsical Cell Village a decidedly cheeky edge. The scene has since become legendary — and now the cast can finally tell the story behind it. The move is supposed to reveal a pair of short shorts underneath, accompanied by the line "I'm wearing them, I'm wearing them" — but recently Lee forgot to put the shorts on, and the reveal became an accidental exposure. Without missing a beat, he delivered the line as "I'm wearing them, I'm wearing them — wait, I'm not!" The audience erupted. Tiffany Young later called it "an iconic scene born from one incredible ad-lib."

The attention to detail among the cast was painstaking. Yeon Ji-hyeon carries much of the show's second half as Writer Cell, but she put equal care into her interpretation of Miser Cell. Born in 1997 and a member of Generation Z, Yeon drew entirely on her own generational sensibility to create the character. "I didn't set her up as someone who is meek because she's poor," she said with a laugh. "She's a cell who is angry about being poor. She's constantly furious at the cells that spend money freely, and the patches sewn onto her clothes are her idea of spending-money fashion — and the slash marks are scars from a fight with Hungry Cell."

Kim Yeong-ung practiced the timing and blocking for switching his light bulb on and off on his own, and devised what the cast calls the "flying squirrel scene," in which he leaps into the arms of Trainee Cell 109 — a moment that maximizes Intuition Cell's signature harmless, endearing charm. Han Jun-yong said he created steps and hand gestures to bring out the twin-couple concept he shares with Rational Cell.

The two cells that flank Love Cell like guardian spirits are distinguished not only by their costumes but by their posture: Rational Cell places the palm of his hand on his waist, while Emotional Cell places the back of his hand there — a subtle but deliberate difference. Han's ideas shine in other moments too, including an ad-lib that plays on the real identity of Tiffany Young, who plays Yumi. In the scene where Yumi ranks her priorities, Han worked in Tiffany's own line from Girls' Generation's "Genie" — "DJ, put it back on" — as a spontaneous nod to the actress's past.

"Looking back now it's a fond memory, but at the time every single moment was the agony of creation," Lee Gyeong-uk said. "Even so, whenever someone said 'let's try it,' not one person frowned — we all swam through that wave of pain together."

All that deliberation and all those ad-libs shine brightest in the opening scene, when every cell appears at once. Just as you might be tempted to dismiss the cells bursting out of the webtoon as something out of a cheap cartoon, you find yourself witnessing the craftsmanship of each individual cell performing with total commitment. The scene the cast loves most is also the opening ensemble number — what they call the "big opening mob scene."

"Every single cell is genuinely giving 1.5 times their share," Yeon Ji-hyeon said. "Even when they're not visible on stage, they exist and react without dropping out of character for even a tenth of a second. The blood, sweat and tears of every actor are condensed into this show."

As the four actors have shaped their own cells, they have gradually come to resemble them. The stage carries a constant warmth, born of the long hours they have spent dissecting and analyzing "Yumi's Cells" more deeply than anyone. All four say the show is "your own story" and "one great twist."

"In Cell Village, there is no major and no minor. Every cell is a precious being that exists with its own sense of mission — to protect the universe that is Yumi, and to make her happy. When you first see the opening, you might look at the gap between the webtoon and the stage and think, 'What is this?' But by the time the show ends, you will find deep comfort in the realization that all these countless cells exist solely for you — crying, laughing and fighting on your behalf."