Storyline:

Baek Do Ha and Baek Do Yeong are twin brothers, but have lived apart since their parents' divorce when they were young. Younger brother Baek Do Ha lives in the United States, and older brother Baek Do Yeong lives in South Korea. Baek Do Ha comes to South Korea and stays in a duplex house with his father and brother, Baek Do Yeong, every summer for 21 days.