Lee Young-jun is a narcissist who can only love himself since he wants a perfect human. The only human that he approves is Kim Mi-so, the meister in Secretary World. One day, Secretary Kim declares resignation when they had perfect chemistry for 9 years?!...

A resignation letter returned as a proposal?! Mi-so rejects his proposal without a pause and starts transition as she has planned. While, Young-jun is in shocked by getting rejected for the very first time from a woman, he receives a tempting advice from his friend Yoo-sik.

Young-jun brings Mi-so in to give tremendous resignation gifts... Mi-so is impressed by new sides of Young-jun, but doesn't last long. Then, Mi-so goes out for a blind date and Young-jun gets to hear Mi-so's plan. Confident but nervous, Young-jun shows unreadable behaviors.

At the end of a fierce battle, Mi-so gets heart attack. Young-jun and Mi-so who find new sides from each other visit an art center. They spend romantic time there. Meanwhile, Sung-yeon who has returned to Korea after 3 years goes to see his brother Young-jun. However, Young-jun's attitude towards his brother seems akward.

Young-jun, who only could love himself, starts racing without stopping towards Mi-so after checking his affections. Meanwhile, Mi-so isn't used to her boss's unfamiliar behaviors. Without knowing that her feelings are tilted toward Young-jun, she stands next to Sung-yeon wearing a pretty dress...

After a kiss, Mi-so takes a day off of her own for the first time in 9 years. However, she doesn't know how to spend her day off since she never did before... She receives a call from a date and finds a someone whom she has been looking for. Meanwhile, Young-jun is not okay with seeing Mi-so's empty seat! In order to ease Mi-so's mind, he decides to join Mi-so's peaceful break...

Mi-so and Sung-yeon become closer as they put the pieces of old memories together. Young-jun keeps his eyes on them and shows shameless affections. Meanwhile, Mi-so goes to workshop with the workers! She is so excited to enjoy the peace until Young-jun appears! All the workers fall into chaos...

Young-jun invites Mi-so to his house. His house used to be her work place. She's just too nervous to visit, but Young-jun has prepared a very special present to impress her. Meanwhile, the grand open of the Yoomyung art center has come close. Sung-yeon makes a surprising statement when many people are gathered during a book concert, and Mi-so is just worried about Young-jun...

Young-jun overcomes his trauma by Mi-so's sincere confession. They finally start dating, however, Mi-so professinally separates her personal affairs from work when Young-jun wants to express his love to everyone.Young-jun is confused.

Mi-so is confident that Young-jun is the one she's been looking for. But wonders why all his family is lying. Therefore, Mi-so goes to see Mrs. Choi in order to make sure her confidence. She finds a conclusive evidence from unexpected place. Meanwhile, Young-jun finds out that Mi-so's sisters aren't okay with him! Then, he joins their family trip to convince them.

Mi-so passes out after remembering kidnapping! Young-jun stays next to her when she opened her eyes just like 24 years ago. Mi-so bursts into tears after reuniting with Young-jun. Meanwhile, Young-jun always wants Mi-so to forget about the incident. He prepares for a special care service for Mi-so.

Young-jun is worried about Mi-so after getting her memory back. Mi-so starts living together with him in her tiny studio. She feels strange tension by seeing Young-jun in her room and thinks she can't sleep well because of Young-jun who came to help her have a deep sleep.

Even though it's clumsy, Young-jun and Mi-so do best for their love! They become fonder as they are seperated from each other for work.

They affirm their love for each other. They think they can go through any hardships, however, they face an obstacle. Then, it even shakes their relationship.

Young-jun's plan for nonchalant proposal gets caught by Mi-so's father. They get to spend a night drinking, but Young-jun is told that her father will not allow the marriage if he doesn't prepare a romantic proposal.

After the romantic proposal, they go straight to the marriage preparation. While preparing for the marrigage, Mi-so seems to focus more on works when Young-jun puts all of his efforts.