Seo Cheon-soo
Seo Cheon-soo is a minor character in Dae Jang Geum. He is the father of Seo Jang Geum and a military guard from the middle class(chungjin). He is the first of all the characters to appear in the series. The series begins as he is practicing for an archery tournament. Then a military officer in the Royal Guards, he is forced by King Seongjong to administer poison to Queen Yun, deposed mother of the next king, King Yeonsangun. Queen Yun dies cursing Seo and the other guards saying that they would die the same way she did; this comes true when her son becomes king and takes revenge for her. While depressed from this, Seo falls down a gorge and is saved by a Taoist hermit, who tells him three women control his fate. He shall kill the first woman, save the second woman who will die because him, and die because of the third woman who will save many lives. Seo is given three Chinese characters that will guide him in finding out if he has met one of the women. The first word is "jin" made by combining "nu"(lady) and "jin"(today). This means he met the first woman that day. The second word is "shun", made by combining "shun"(flow) and "dao"(head). This means the second woman Seo will find her with her head submerged in flowing water. The third word is "hao"(good), which is made by combining "nu"(lady) and "zhi"(son). This means the third woman will be the daughter Seo has by the second woman.
Seo immediately knows the first woman is Queen Yun. Fourteen years later, Seo comes across Park Myeong-yi just after she was deposed of by the Royal Kitchen. Her head is under water like she is drowning. Without remembering the hermit's words, Seo saves her and takes cares of her as she leaves. Finally, he remembers the word "shun". The clue of Myeong-yi's head bg under flowing water gives her away. Park Myeong-yi is the second woman. Feeling she owes her life to Seo for saving her, Myeong-yi follows and marries Seo. For eight years they live in hiding as cheonmin, raising their bright daughter Seo Jang Geum.
Now King, Yeonsangun visits his grandmother(Queen Yun's mother) and she tells him how his mother died. She gives him a handkerchief with his mother's blood on it proving her execution. Yeonsangun becomes enraged and psychotic which causes him to look for all who participated in his mother's execution to take revenge.
When her father is in trouble Jang Geum immaturely blurts out the truth that her father was a military guard. Seo is discovered to be the guard who poisoned the mother of Yeonsangun. Seo is executed and the third woman is discovered to be Jang Geum.