When a Man Is in Love.

After the death of his mom, Ji Hoon moves into the home of Mr. Seo. Ji Hoon falls in love at first sight with Mr. Seo's daughter, In Hye. Ji Hoon also becomes good friends with Seok Hyeon. But one day, In Hye decides to leave home for Seoul to pursue her dream of becoming an accomplished cellist, without telling Ji Hoon. Seok Hyeon also decides to move to Seoul after he learns that he is the love child of President Kang, a wealthy hotel magnate. When Ji Hoon finds out that In Hye left for Seoul without even saying goodbye, he finds his way to Seoul to find her. One day, while Ji Hoon is riding the subway, Jung Woo takes a liking to him and decides to steal his wallet to get his attention. Through this incident, Ji Hoon gets to know Jung Woo and settles down in Seoul by enrolling in the same bodyguard school that Jung Woo is attending. The bodyguard training school finds a part-time job for Ji Hoon and Jung Woo, which is an assignment to guard President Kang for one day.