The premise fits in a sentence: everything a person feels or decides is staged as a meeting of the cells inside her head. A hunger cell, a love cell, and a rational cell argue it out, and whatever they settle on leaves the office worker Kim Yumiโs mouth as a single line or shows up on her face as a single expression. Lee Dong-gun posted the opening and episode 1, โKeeping a Straight Face,โ on the same day, April 1, 2015, in Naver Webtoonโs Saturday slot, and finished with โEndingโ on November 6, 2020. Counting the authorโs afterword a week later on November 13, Naver lists the run at 512 episodes. It is rated 12 and up, and nearly six years after the last episode 1,306,531 readers still have it saved.
The awards came while it was still running. It was named to Todayโs Our Manhwa in 2016, a yearly list picked by Koreaโs culture ministry and the Korea Manhwa Contents Agency, and in 2018 it took the Presidential Award in the comics category at the Korea Content Awards. Coverage at the time of its ending in November 2020 put it at roughly 3.2 billion cumulative views and 5 million comments; the 2026 musical announcement cited 3.5 billion views worldwide. The translations have held up too. The English edition on WEBTOON has 744,477 subscribers and 204.2 million views, the traditional Chinese ๆ็พ็็ดฐ่ๅฐๅฐ has 37.2 million views, and the Japanese edition ran on LINE Manga as ใฆใใฎ็ดฐ่ใใก at the full 512 chapters.
Screen adaptations started with television. Season one, a TVING original that also aired as a tvN Friday-Saturday drama, ran 14 episodes from September 17 to October 30, 2021, with Kim Go-eun as Yumi and Ahn Bo-hyun as Goo Woong. Its trick was switching inside a single episode between live-action scenes and 3D animated ones for the cells. Lee Sang-yeop directed, and the script was by Song Jae-jung, Kim Yoon-joo, and Kim Kyung-ran. Season two went up on TVING first in June 2022, then aired on tvN from November 16 to December 29 the same year, with Park Jin-young joining as Yoo Babi.
The animated feature, Yumiโs Cells: The Movie, opened on April 3, 2024. Kim Da-hee directed the 93-minute 3D film, produced by Locus and Studio N, rated for all ages, and it drew 76,602 admissions. It covers the stretch where Yumi quits her job to enter a writing contest, with Yoon A-young voicing Yumi. This year the story moved onto a stage. The musical opened on June 30, 2026 at the CJ Towol Theater in the Seoul Arts Center and closes with the August 23 performance. Tiffany Young and Kim Ye-won alternate as Yumi, Yang Jung-woong directs, Kim Ga-ram wrote the book, Choi Jae-kwang composed, and Sam Company produced it with Studio N.
The webtoon is complete and open from episode 1 on Naver Webtoon, and the English and traditional Chinese editions are still up on WEBTOON. Do not let the number 512 put you off. Episodes are short strip-style installments, and the relationship arcs break cleanly enough that you can stop anywhere and come back. If you met this through the drama or the film, the draw is seeing what the cells actually said on the page first; if romance is not usually your genre, the draw is the device itself, a personโs feelings staged as coworkers arguing in a conference room. (As of August 21, 2026)
