On the eve of the founding of the Joseon Dynasty, a whale swallows the Emperor's Seal of State being brought to Joseon by envoys from China. With a big reward on whoever brings back the royal seal, mountain bandits led by Jang Sa Jung go out to sea to hunt down the whale. But he soon clashes with Yeo Wol, a female captain of pirates, and unexpected adventure unfolds.
Shin Se Kyung and Shin Shin Ae (Seo Shin Ae) are a pair of sisters who came to work as maids in Foodstuff company President Lee Sun Jae's house after their debt-ridden father Shin Dal Ho (Jung Seok Yong) runs away leaving them to fend for themselves. Due to the sisters living their lives in the mountains, everything in the city (outside world) are both new and curious for them especially for the younger sister, Shin Ae. Living together with President Lee is his daughter Lee Hyun Kyung, son-in-law Jung Bo Suk, doctor-to-be son Lee Ji Hun, grandson Jung Jun Hyuk who is a high school student and grand-daughter Jung Hae Ri' Jun Hyuk's school deen, Kim Ja Ok, is in love with President Lee who is widowed.