The self-sounding drum caused neighboring nations, including the warrior state of Goguryeo, to hesitate about attacking Nakrang.

[citation needed] The period drama series, however, gives a new twist in that the drum is in fact a person, embodied by Ja-myung, the hidden sister of the Nakrang Kingdom's princess.

Growing up as the princess of Nakrang, Ra-hee is adored by her people, while Ja-myung survives a murder attempt and lives as a commoner.

Prince Hodong, from Nakrang's enemy, the Goguryeo Kingdom, is torn between two nations and two women, and must make a choice between love and duty.

Ja-myung survives an assassination attempt by her stepmother Wang Ja-shil (Lee Mi-sook), the ambitious mother of Ra-hee.