Who is Yul Kim from This Burns My Heart: A Novel and what is their importance?

Yul Kim is the leader of the student protestors when Soo-Ja meets him. Yul is an intelligent and gentle man who quickly wins Soo-Ja's affections. They are drawn to one another quickly, but Yul hesitates in showing his affections to Soo-Ja, giving her the time necessary to solidify things with Min. When Yul finally asks Soo-Ja to marry him, she rejects him because she is afraid of having to explain to him why she gave herself to Min outside of marriage. The reader also suspects that perhaps Soo-Ja already knew she was pregnant and did not want Yul to be faced with marrying not only a woman with loose morals, but a woman who will be giving birth to another man's child.