After suffering a painful breakup, Yu Mi’s love cells have shut down completely, but a chance meeting with the emotionally stunted game designer, Goo Woong, changes all of that. Waking up a number of each other’s cells, Yu Mi and Goo Woong find themselves drawing closer, but even with the revival of their long-dormant love cells, their relationship wasn’t destined to last. Now a much wiser and more mature individual, Yu Mi finds herself willing to take on a set of challenges after an unexpected source of inspiration ignites her internal fire. Inspired by her co-worker, Bobby Yoo, Yu Mi and her hard-working cells set out to make all of her dreams come true. Adapted from the webtoon "Yumi's Cells" (유미의 세포들) by Lee Dong Geon (이동건).