Yumi's Cells () is a South Korean manhwa series written and illustrated by Lee Dong-gun. This webtoon was released on internet portal Naver from April 1, 2015, to November 13, 2020, with a total 512 chapters. The story revolves around Kim Yumi, a 32-year-old office worker, and her brain cells, tiny blue-hooded cells that control her every mood, thought, and action.
A live-action drama, titled Yumi's Cells, was released on September 17, 2021, in South Korea. On September 8, 2021, TVING announced that the drama had sold broadcast rights in more than 160 countries around the world, including Europe, North America, and Southeast Asia.
The animated film titled ' was released on April 3, 2024, in South Korea.