Yoon Tae In is the leader of the idol group, Luna. He suffers from sleepwalking. To cure his ailment secretly, a fake doctor begins to live with him. In Yoon Joo works as a tour guide. Her dream is to one day buy her own house. She happens to get involved in an incident and begins to live as a fake doctor with the 5 members of Luna: Yoon Tae In, LeeShin, Kim Yoo Chan, Woo Ga On, and Seo Woo Yeon.
(Source: AsianWiki)