Sin Eun Hye is disabled, but her beautiful heart and permanently sunny personality earned her the fond description of being a 'happy virus.' She dreams of studying in Seoul, and with the help of Madam Min Hye Sung, the head of Sorabol Hotel, Eun Hye becomes her grandson Philip's tutor and is able to read many books in the rich old lady's library. She later falls in love with Min Hye Sung's ambitious oldest grandson, Lee Hyeong Cheol, and begins a trial of love and hardships that she must face on her way towards achieving both physical and spiritual healing.