Based on the eponymous webtoon, it is a cell-based psychological romance that unravels the daily life of an ordinary office worker Yumi through the eyes of the cells in her head.

[8] 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 drama tells the story of an ordinary office worker from the perspective of the brain cells in her head that control her every thought, feeling and action.

On December 31, 2020, it was reported that webtoon Yumi's Cells published on Naver by Lee Dong-gun with 3.2 billion accumulated views was being made into a television series and Kim Go-eun was confirmed as the female lead.

[33] On June 18, Ahn Bo-hyun revealed in an interview that he was currently filming Yumi's Cells and he has developed naturally tanned skin tone for the role of Goo Woong.