Psychology student at a top university that thinks dating, sex and love don't always go together
Not only does she have feminine, adorable and sometimes provocative looks, but is also intelligent. She was born the only daughter of a well-off, happy family. Doo Ah's life was always peaceful and she was always happy. She's never felt despair in her life. One thing she lacked since she was a child is female friends, but she has Han Wool. Do Han Wool, who lives downstairs, is her friend, brother and lover. It would have been nice if the relationship lasted forever, but it became a problem when they started dating as he joined the army. They didn't know they could still be friends after sleeping together once. Doo Ah believes a person's mentality and human nature can be understood through analysis and research, and she approaches loves, dating and break-ups as if one would approach studies. Dating three men at the same time is no challenge for smart Doo Ah. However, Doo Ah's secret is exposed on Daesoop, her alma mater's community, and her life become chaotic as it is turned totally upside down.
