Young-Woong is a psychiatrist (Kim Kyeong-Ik). He has been married to Soo-Hyun (Jin Hye-Kyung) for 10 years, but their love has waned and they now feel indifferent towards each other. One day, Soo-Hyun's daughter Haru (Ayaka Tomoda) appears before them. Soo-Hyun gave birth to Haru while she was studying in Japan. Haru carries a wounded heart from her boyfriend's betrayal. Soo-Hyun asks Yoong-Woong to treat her daughter. Through their consultations, Young-Woong begins to dream of more than just a doctor and patient relationship.

There's a relationship no one should know about.
　　Psychiatrist Yeong-woong and his wife have been married for 10 years. They've lost interest and now neglect each other. Life is just a dull routine for them. Then one day, Haru, a child Soo-hyeon had when she was a student in Japan shows up in front of them hurt and exhausted from her boyfriend's betrayal. Soo-hyeon asks Yeong-woong to treat her and as a psychiatrist, he does his job. However, as the sessions progress Yeong-woong feels more for Haru than he should and starts thinking of a relationship beyond a doctor and a patient...