Yumi's Cells Webtoon vs. K-Drama: 5 Adaptation Differences That Matter

Spoiler level: None beyond the opening premise. This comparison covers storytelling formats, production choices, and the differences between reading the webtoon and watching the drama. It avoids later relationships, major plot turns, and endings.

In Yumi’s Cells, a perfectly ordinary moment can become a very crowded conversation. Yumi might have only a few words to say, but inside her head, her cells have plenty of opinions.

That’s the idea at the heart of Donggeon Lee’s Korean webtoon. When it became a K-drama, however, the creators faced a tricky question: how do you bring those tiny, expressive comic characters into a world occupied by real actors?

The solution was unusual. Rather than removing the cells or turning everything into live action, the drama combines Kim Go-eun’s performance as Yumi with 3D animated characters representing her inner world.

It’s more than a visual upgrade. It changes how viewers experience her thoughts, the jokes, and the distance between what Yumi feels and what she actually says.

The main difference: The webtoon makes Yumi’s inner life part of the comic’s visual language. The drama gives that inner life movement, sound, and performances of its own.

Here are five differences worth understanding before choosing where to start.

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Yumi’s Cells: Webtoon vs. K-Drama at a Glance

Feature	Original Webtoon	K-Drama Adaptation
Original creator	Donggeon Lee (이동건)	Based on Donggeon Lee’s webtoon
Main format	Vertically scrolling Korean digital comic	Scripted television drama combining live action and 3D animation
Yumi’s presentation	Illustrated character	Played by Kim Go-eun
The cells	Drawn characters within the comic	Moving 3D animated characters with voice performances
Story rhythm	Short serialized comic installments	Television episodes organized into seasons
Original publication	Korean webtoon completed in 2020	Three drama seasons released in 2021, 2022, and 2026
Official starting point	Korean Naver WEBTOON or English WEBTOON	TVING in Korea; international services vary by region and season

The original Korean webtoon is complete, with 512 episodes listed on Naver WEBTOON. The official English WEBTOON is also marked completed.

The television adaptation has three seasons, including a third season released in 2026.

That doesn’t mean the two versions can be matched episode for episode. A comic installment and a television episode are different storytelling units.

1. The Cells Move From 2D Drawings to 3D Animation

The most obvious difference is also one of the most interesting.

In the webtoon, Yumi’s cells share the same illustrated medium as everything else. Her everyday life and her inner world may look different, but both are part of Donggeon Lee’s visual storytelling.

A small reaction can interrupt a larger scene. A cell’s expression can make a thought funny before anyone in Yumi’s outside world has said a word.

The drama has a different problem to solve.

Yumi’s outside world is performed by live actors, while her inner world remains animated.

That makes the boundary between the two more visible. The audience moves between recognizable human performances and a miniature world that follows its own visual rules.

How the Animation Team Approached the Cells

The production did not simply copy the webtoon’s drawings into three-dimensional models.

In a 2021 interview published by Korea.net, a representative of Sidus Animation Studios described the challenge of translating the original cells into moving characters while retaining their recognizable appeal.

The studio developed a more complete environment for the cells, including the surroundings in which they live. Movement and character performance also required creative decisions that a still comic image does not.

That’s a substantial adaptation task.

A drawing suggests motion through its composition and sequence. Animation has to decide exactly how a character moves, how quickly it reacts, and what happens between expressions.

For someone who particularly enjoys the webtoon’s artwork, this is one of the clearest reasons to try the drama.

It offers another interpretation of the same imaginative idea, rather than merely displaying the existing panels on a television screen.

2. The Cells Gain Voices, Timing, and Sound

Reading a webtoon is a partly private performance.

You see the dialogue and decide how it sounds in your head. You control the pace of each scroll and how long you stay with an expression.

A drama makes more of those decisions for you.

The cells have voice actors. Their conversations come with specific vocal personalities, pauses, and emotional delivery.

According to the Sidus Animation Studios interview, voice performances were recorded before the main animation work. Animators then used those recordings, along with reference material from the performances, when developing the finished scenes.

This is a useful detail because it shows that the animated cells were treated as performing characters, not simply decorative effects.

Why the Voices Matter

Imagine a character saying something sensible while sounding deeply offended.

The words are only half the joke.

Volume, hesitation, rhythm, and tone can change whether a line feels serious, anxious, or ridiculous.

The webtoon achieves its effects through writing and drawings. The drama adds the choices made by voice actors and animators.

The 2021 Korean interview with director Lee Sang-yeob and the writing team also describes deliberate attention to the cells’ vocal tone.

The production wanted the cells to feel connected to an adult woman’s inner life, rather than simply sounding like children because they look small and cute.

That’s an important distinction.

The cells are playful characters, but the feelings they represent aren’t necessarily childish.

3. Kim Go-eun Gives Yumi’s Outer Life a Different Presence

There are really two performances of Yumi in the drama.

One takes place on the outside, where Kim Go-eun plays her through expressions, dialogue, and physical reactions.

The other takes place among the animated cells, where viewers encounter thoughts that Yumi may never say aloud.

The webtoon creates that contrast on the page. Both the external behavior and the inner reactions are drawn by the same creator.

The drama distributes those responsibilities among actors, writers, animators, and voice performers.

That changes the reading experience into a viewing experience.

What This Means for Yumi’s Character

In a comic, readers can spend as long as they like noticing the gap between a character’s face and her internal response.

A live-action performance gives that gap a particular rhythm.

An actor can let a look or pause linger while the animated cells reveal a much busier emotional state.

Those two levels don’t always need to agree. In fact, the distance between them is part of the premise’s appeal.

The drama also gives viewers a specific human face and voice to associate with Yumi.

In the webtoon, Donggeon Lee’s illustrated character remains the defining visual version.

Neither is automatically more authentic. One is the original drawing; the other is a performed adaptation.

If you prefer imagining a character’s voice from the page, the webtoon offers more room for that. If you enjoy the nuances of screen acting, the drama provides something the original medium cannot deliver in quite the same way.

4. The Story’s Pacing and Adaptation Choices Are Different

The webtoon began in 2015 and finished in 2020. It was written for a serialized comic format, where individual installments could focus on everyday situations, inner reactions, or a specific emotional problem.

The K-drama must organize that material into television episodes and seasons.

Those formats create different pressures.

A comic can spend a short installment exploring a feeling or an awkward interaction. A television episode needs to balance multiple scenes, performances, and transitions within a scheduled running time.

That doesn’t mean the drama simply removes everything that won’t fit.

It can rearrange or develop material to make a television episode work.

Is the Drama Exactly the Same as the Webtoon?

No. The production team has acknowledged making adaptation choices.

In a November 2021 interview with NewsPim, the drama’s writers discussed the challenge of combining live action and animation.

They also described the second season as incorporating new material while retaining the original story’s framework.

That makes it inaccurate to expect a one-to-one reproduction of the comic.

It’s equally inaccurate to assume that every difference is a mistake or a betrayal of the original.

A change might be made for episode structure, screen performance, or the relationship between animation and live action.

Without comparing particular scenes directly, however, it’s better not to invent a list of supposedly deleted moments or rewritten character decisions.

The reliable conclusion is that the drama adapts the source rather than reproducing its exact episode sequence.

5. One Complete Webtoon, Three Drama Seasons

The two versions also ask for different kinds of commitment.

The original Korean webtoon is a completed series. Readers can move through its episodes at their own pace, subject to the platform’s current access rules.

The drama is arranged into three seasons.

Its first season debuted in 2021, the second in 2022, and the third in 2026.

CJ ENM’s official information identifies Season 3 as an eight-episode production and confirms Kim Go-eun’s return.

The completed webtoon and the drama’s three-season structure should not be treated as interchangeable measurements of story length.

A single drama episode can combine material that appeared separately in the comic. And the drama can introduce television-specific scenes or alter the emphasis of an existing situation.

For someone who likes watching an ongoing character journey in clearly organized seasons, that structure may be appealing.

For someone who prefers choosing when to stop and resume, the webtoon’s individual installments may feel more flexible.

There is no reliable universal conversion such as “one drama episode equals a certain number of webtoon chapters.”

A Korean Detail: What You Show Isn’t Always What You Feel

One of the reasons this premise works is the tension between outward behavior and private emotion.

The first numbered Korean webtoon episode is titled 표정관리 (pyojeong gwanri), an expression used for controlling or managing one’s facial expression.

You might be trying not to look disappointed, irritated, nervous, or overly excited.

The situation is recognizable well beyond Korea. But the Korean expression offers a particularly neat way to understand the story’s recurring contrast.

On the outside, Yumi may be trying to manage her expression.

On the inside, her cells have their own reactions.

The webtoon can represent that contrast with a shift between illustrated scenes. The drama can put a live actor’s restrained expression beside a much louder animated response.

The joke is similar, but the performance changes.

That is also why Yumi’s Cells shouldn’t be understood as a scientific explanation of how thoughts work. Its cells are fictional characters that make internal experiences visible.

And Yumi’s experiences should not be treated as a universal description of Korean women or Korean office life.

The value of the premise comes from how one fictional character’s ordinary moments become unexpectedly complicated.

Which Version Should You Start With?

Both are reasonable starting points, but they offer different strengths.

Start With the Webtoon If…

You want the original storytelling format.

Donggeon Lee created Yumi’s Cells as a webtoon, not as an adaptation of an earlier prose novel.

The original comic lets you encounter the cells through the artwork, panel rhythm, and serialized storytelling that first defined the series.

It’s also the clearest verified option if you want to read the original story in English.

You can start with the official English Yumi’s Cells on WEBTOON.

Readers comfortable with Korean can also visit the original Naver WEBTOON edition.

Start With the K-Drama If…

You prefer watching Korean television to reading long digital comics.

The combination of Kim Go-eun’s performance, animated cells, voice acting, and music creates a distinct experience.

You may especially enjoy the drama if you’re curious about how a highly visual comic idea can work alongside real actors.

My Yumi’s Cells Season 1 review shares how that combination felt to watch, including the relatable emotions, Kim Go-eun’s performance, and moments when the relationship tension frustrated me.

In Korea, TVING is an official place to start with the first season.

International streaming availability depends on location and season.

CJ ENM confirmed distribution of Season 3 through HBO Max in selected Asia-Pacific territories and Disney+ in Japan, but that announcement does not establish worldwide availability for every season.

Check the local catalog before purchasing a subscription.

What If You’ve Already Watched the Drama?

The original webtoon is still worth considering if you want to see how the cells were first drawn and how the story was originally organized.

You don’t have to assume that the drama’s episode order maps neatly to the comic.

And starting the webtoon from the beginning is a reasonable choice if your goal is to appreciate the original presentation rather than search for an approximate continuation point.

Final Verdict: Same Inner World, Different Creative Tools

The most interesting achievement of Yumi’s Cells is that its central idea can work in two different visual forms.

Donggeon Lee’s webtoon makes Yumi’s thoughts into characters on the page. The drama takes that concept into live action, animation, sound, and performance.

The 3D cells aren’t simply the webtoon’s drawings with extra movement. They’re the result of a separate creative process.

Likewise, Kim Go-eun’s Yumi is a screen interpretation of the original character, not a replacement for Donggeon Lee’s version.

Choose the webtoon if you want the original comic and control over your own reading pace. Choose the drama if you want to see the cells perform alongside live actors.

If you’re interested in how Korean webtoons become screen adaptations, trying both gives you two different ways to understand the same clever premise.

For a broader introduction to the original creator, Korean title, other adaptations, and reading options, visit the Yumi’s Cells title guide.

Official Sources and Further Reading

• WEBTOON — Yumi’s Cells — official English webtoon, creator, and completion status.
• Naver WEBTOON — 유미의 세포들 — Korean original, opening episode titles, and completed episode catalog.
• TVING — Yumi’s Cells Season 1 — official Korean drama listing.
• CJ ENM — Yumi’s Cells Season 3 — season format, official cast, and production information.
• CJ Newsroom — Season 3 International Distribution — regional platform information released in March 2026.
• Korea.net — Interview With Sidus Animation Studios — 2021 interview about adapting the cells into 3D and creating their performances.
• NewsPim — Interview With the Yumi’s Cells Director and Writers — 2021 Korean-language interview about the animation, acting, and adaptation approach.