Jang Seon-gyeol is a young, wealthy CEO of a cleaning company who suffers from severe mysophobia, an intense fear of germs and dirt. He views cleaning as both his mission and the highest form of human achievement. His life turns upside down when he crosses paths with Gil O-sol, a bright and energetic job seeker who is too busy struggling with the harsh realities of life to care about tidiness, ultimately becoming an employee at his company. As Seon-gyeol and O-sol are forced to work closely together, their starkly contrasting worlds collide, leading to hilarious situations and unexpected emotional healing. Seon-gyeol must confront his deeply rooted psychological trauma to be with O-sol, while O-sol rediscovers her self-worth and passion. Together, they navigate societal pressures, family secrets, and the messy, unpredictable nature of falling in love.