In episode 10 of MBC's Friday-Saturday drama "21st Century Grand Lady," Seong Hee-joo (played by IU) decides to divorce Prince Ian (played by Byun Woo-seok) to quell the controversy surrounding him and directly declares the divorce to Prince Ian. Following advice from her father Seong Hyun-guk (played by Jo Seung-yeon), Seong Hee-joo realizes that she is Prince Ian's weakness and officially announces the divorce in front of the ministers. Additionally, her older brother Seong Tae-joo (played by Lee Jae-won) holds a press conference taking responsibility for the contract marriage and attempts to ease public opinion by spreading rumors about the poisoning incident at the wedding.

During this process, Seong Hee-joo tearfully says, "Let's get a divorce," and Prince Ian responds, "What are you talking about?" Seong Hee-joo pushes for the divorce, mentioning the company and family, and turns her back saying, "Let's just break up now." She then firmly states, "It's not just my fault. It's a shared mistake. But I don't want to suffer any more losses."

Prince Ian, shocked by Seong Hee-joo's sudden decision, shows tears and says, "Don't do this. Even you to me." Seong Hee-joo emphasizes, "You said you didn't want to tie me down. Now you're only losing me. Yet you still want to keep me tied down?" She also asks the ministers to have her declared a disgraced royal family member and subjected to investigation.

Meanwhile, Prime Minister Min Jung-woo (played by Noh Sang-hyun) begins to take action to prevent Seong Hee-joo from taking all the responsibility. King Lee Yoon (played by Kim Eun-ho) met with Prince Ian the previous night and expressed his intention to abdicate the throne, but Prince Ian refused once. After the abdication edict was issued three times, the situation forced Prince Ian to accept the abdication.

Prince Ian leaves the palace and heads to his private residence, and Seong Hee-joo contacts him to confirm his whereabouts. Later, Seong Hee-joo sincerely confesses, "I like you," and the two confirm their feelings for each other and spend the night together. Prince Ian responds to Seong Hee-joo's confession with "No" and answers with a kiss.

Episode 10 of "21st Century Grand Lady" aired on the 9th at 9:40 PM.