Gil Oh-so, an employee at a cleaning company, meets Jang Seon-gyul, the boss of the company. The two are diametric opposite when it comes to cleanliness. With the help of Oh-sol, Seon-gyul faces his mysophobia and falls in love with her.
While looking for his beloved robot vacuum, fastidious CEO Jang Seon-gyeol runs into Gil O-sol, a job seeker who doesn’t mind a bit of untidiness.
Seon-gyeol gives O-sol one week to pay for damages. Growing more desperate, she decides to apply to one more place, where her skills may come in handy.
O-sol runs into Seon-gyeol at her new job. When he later finds her drunk on the street, he reluctantly gives her a ride home but ends up regretting it.
Seon-gyeol wakes up in the hospital but has no idea how he got there. O-sol tries to comfort her father and astounds everyone at work with her new look.
Seon-gyeol makes a rash decision that he soon regrets but keeps doing things he can’t explain. O-sol is stunned to learn about Seon-gyeol’s condition.
Seon-gyeol becomes distraught when he learns about O-sol’s new assignment, but can’t get hold of her. O-sol is bewildered by Seon-gyeol’s actions.
Baffled by Seon-gyeol, O-sol pours her heart out to a neighbor. Distracted at work, Seon-gyeol comes to realize something -- but it may be too late.
Choe Ha-in’s revelation catches O-sol off guard, but his words keep swirling in her mind. O-sol helps Seon-gyeol during a precarious situation.
O-sol grasps what her job means to her and resumes work. When she’s falsely accused by a client, Seon-gyeol defends her, putting the company at risk.
Seon-gyeol is puzzled to find O-sol at his place, but things get more awkward when his mom stops by, and he later sees changes at home and in himself.
O-sol is perplexed by Seon-gyeol’s attentive behavior. Seon-gyeol panics when an unwelcome visitor arrives, and his mother later asks O-sol for a favor.
O-sol keeps telling Seon-gyeol that she’s not looking to date, but he arranges an impromptu surprise for her and reveals another side of himself.
Seon-gyeol admits O-sol is the first person to be empathetic about his quirks, but she decides to move out after coming to terms with her feelings.
Seon-gyeol is resolute about curing his mysophobia, but O-sol reaches a drastic verdict after her family discovers his grandfather’s identity.
Devastated by his grandfather’s revelation about AG Group, Seon-gyeol discovers he’s been betrayed by someone he implicitly trusted.
O-sol hears that Seon-gyeol is leaving for the U.S. O-sol’s family receives an overdue apology. Seon-gyeol wants to start over, but it may be too late.
