Choi Jae-rim is building self-esteem, onstage and off

Choi Jae-rim, one of the most sought-after actors in Korean musical theater, plays 109, the self-esteem cell in “Yumi’s Cells,” a new musical based on the hit webtoon. The role was built from scratch for the stage, with no counterpart in the original webtoon — and it’s the cell he wishes everyone had.

Why wish that on everyone? Because in his own definition, self-esteem isn’t just self-belief; it’s belief backed by evidence.

“You keep a clear, objective eye on reality while never losing faith in yourself,” Choi said on July 23 during a group interview in Seocho-gu, Seoul. “Believe in yourself without looking at reality, and that’s delusion, not self-esteem.”

For Choi, if there’s a version of yourself you want to become, you have to see clearly where you actually stand, do the work to close the gap — only then can you claim it.

This relentless demand for objective self-assessment is more than an acting exercise; it’s how Choi navigates his own life. When asked about a string of overlapping-cast controversies that trailed him a few years ago, he didn’t reach for a rehearsed line.

“Calling it self-reflection feels like the wrong word,” he said. “It wasn’t something that should have happened, but once it did, there wasn’t much choice but to accept it.” Rather than growing defensive, he analyzed the mechanics of what went wrong —whether it was bad luck or a judgment that had dulled.

Refusing to treat it as a closed chapter, he continually checked himself against it. Case in point: This past February, after noticing the sharpness in his singing had quietly dulled, he quietly restarted vocal lessons. He called it simply “one of those efforts.”

The 41-year-old actor joined “Yumi’s Cells” later than most of the cast, drawn largely by the chance to finally work on something original. Even so, by his own account, the decision did not come easily.

“There were points I went back and forth on,” Choi said. “But between something positive I saw in the script and my own itch to bring years of licensed-production experience into something original.”

That’s not an idle claim. Debuted in 2009 as Collins in “Rent,” Choi has since built one of the genre’s most decorated resumes, but mostly a licensed-production one: Gabe in “Next to Normal,” Judas in “Jesus Christ Superstar,” Lola in “Kinky Boots,” Gringoire in “Notre Dame de Paris,” Radames in “Aida,” Billy Flynn in “Chicago,” Hermes in “Hadestown,” Shakespeare in “Something Rotten,” the Phantom in “The Phantom of the Opera” and Jean Valjean in “Les Miserables.”

After years inside the licensed-production machine, restaging other countries’ hits, he wanted a real shot at something original. He sought a chance that could test whether everything he’d learned could actually feed into how a Korean musical gets built from the ground up, not just remounted.

There’s no version of 109 anywhere else. That meant there was no character to reference. No panel in the original webtoon, no established personality to inherit — just a premise. What would self-esteem look like if it took human form?

Choi built outward from there, starting with himself. “How my character shows up onstage isn’t that different from how I actually am,” he said. Onstage, that means near-constant motion: loud, sprinting, unfiltered.

For most of Act One, 109 barely thinks before acting, because that, Choi reasoned, is what an emotion looks like before it’s been through anything. Only near the act’s end does he start to stop and consider. By Act Two, he’s learned to persuade rather than charge, to listen rather than insist.

“The character was finished at the dress rehearsal,” Choi said, noting that every line is locked to one tone, but that the arc itself was settled by then. What deepens from show to show is precision, not direction.

Looking ahead, Choi was confident that the emotional core of “Yumi’s Cells” — the reassuring feeling that you carry an entire inner world rooting for you — can resonate anywhere.

Yet he remained clear-eyed about whether the current production is ready for the West.

The score leans closer to K-pop than traditional Broadway or West End structures, he noted, and the stage — crowded with dozens of cells tracking two parallel storylines — risks overwhelming uninitiated audiences.

“I wouldn’t say it was written in the musical-theater technique they’d expect there,” he said. Before taking it global, he envisioned a sharper narrative throughline and recalibrated staging — whether for Japan, elsewhere in Asia, or eventually Europe and the US.

“Yumi’s Cells” runs at the CJ Towol Theater inside the Seoul Arts Center through Aug. 23.