Go Yi-seok (Chun Jung-myung) is a successful psychiatrist with a best-selling book and talk show appearances under his belt. Though loving, sensitive and caring towards his family, he is also insecure, egocentric and suffers from an inferiority complex, caused by his childhood experiences. The resulting juvenile behaviour renders him incapable of forming meaningful relationships with women. To make matters worse, he's gradually developing a phobia of his patients, being unable to empathise with their whining - which drives him to drink while on duty.
Cha Hong-do (Choi Kang-hee) is a bright, confident and opinionated woman, whose uncontrollable blushing has left her with crippling sociophobia and caused her to drop out from high-school. She ventures outside her home only when shielded by a helmet and works under disguise as an old grandmother. She nurses a crush of seven years on the kind detective Jang Doo-soo (Lee Jae-yoon) and expresses her feelings by secretly delivering food to his doorstep with notes.
A chance hearing of Doo-soo's blind-date arrangements and upon reading Yi-seok's book, Hong-do is spurred and encouraged to approach Yi-seok's clinic for treatment, so that she can speak to Doo-soo freely face-to-face. A disastrous first encounter leads to Hong-do mistakenly accusing Yi-seok of murder and ends with Yi-seok discovering his phobia disappears when Hong-do is around, while she uncovers his vulnerable side hidden underneath the swagger.
Mutual dependency forces the two to work together, and both slowly realise how beneficial their companionship is to each other. His skill as a psychiatrist allows her real self to blossom into the open, while her inner strength and steadfastness helps him overcome his hidden insecurities.
Entanglements arise when Doo-soo belatedly realises his own feelings for Hong-do and begins to pursue her actively, throwing a spanner into the budding relationship. To complicate things further, Yi-seok's sister Go Se-ro (Ahn So-hee) falls for Doo-soo. Things come to a head for the couple when the Go family's dark past begins to unravel and threatens to drive a nail into the coffin of their bond.