The series is about the office workers of Marketing Team 3 at the home appliance headquarters of Gaus Electronics—a multinational company. It highlights the highs and lows of corporate life, and love and friendship between the employees.

An AI programmer accidentally develops an AI program called Cho Sang Shin, which will identify trashy humans, and she uses it to save people who are in difficult relationships.

Renowned 70-year-old poet Lee Jeok-yo falls for a 17-year-old girl named Eun-gyo. Upon realizing his love for the teenager, the poet goes through emotional turmoil and self-destruction, while willing to give up his fame as one of the nation’s most respected literary figures. Involved in the love triangle is Lee's student Seo Ji-woo, a novelist in his 30s who also becomes obsessed with the girl.