In 'Undercover High School,' Jin Ki-joo and Seo Kang-joon faced each other again as teacher and faculty member.
In the newly aired MBC drama 'Undercover High School,' which premiered on the 21st, Jeong Hae-seong (played by Seo Kang-joon) was depicted infiltrating a hospital.
On that day, Jeong Hae-seong found himself at an underground market. Team Leader Ahn (played by Jeon Bae-soo) said, "The support team has arrived at the scene, so I will follow shortly. So you just track them down," but Jeong Hae-seong replied, "I don't have time for that. If I go any further, I'll reach the downtown area, and we need to catch them before then." He stormed the scene.
In that way, Jeong Hae-seong subdued the Chinese broker and Park Sa-jang with Koh Young Technology (played by Jo Bok-rae) and was able to protect the cultural properties amid the flames. However, the cultural property was damaged due to the gunshot fired by Jeong Hae-seong. He angrily exclaimed, "Who shot a gun here?" then realized it was himself and covered his mouth.
Team Leader Ahn received orders from the Director General, stating, "Find the gold bullion hidden by the national traitor Seo Byeong-moon. The operation name is 'Undercover High School.'" He asked to retrieve the gold bullion worth 800 billion won that Seo Byeong-moon (played by Kim Eui-sung) had embezzled. Upon hearing this, Jeong Hae-seong replied, "Are you crazy? This doesn't make any sense. How am I supposed to go to school?" Team Leader Ahn urged, "You look very young; it's said you aged because you took medicinal tonics when you were young."
Later, after finishing a dinner with the National Intelligence Service team, Jeong Hae-seong stayed alone in a restaurant, deep in thought. This was because he realized that if he didn't carry out the undercover mission at Byeongmun High School, the team would be at risk of disbanding.
Meanwhile, the restaurant owner's daughter and part-time teacher at Byeongmun High School, Oh Su-a (played by Jin Ki-joo), returned after wrapping up dinner and instantly fell in love at first sight upon seeing Jeong Hae-seong. She remarked, "He's really handsome," and while admiring him, she intervened when a group of delinquents threatened her mother with false reports. Just as the delinquents were about to hit Oh Su-a, Jeong Hae-seong easily subdued them and vanished. Oh Su-a exclaimed, "Mom, my heart is racing," showing her infatuation.
A few days later, having transformed into a high school student and entered Byeongmun High School, Jeong Hae-seong faced teacher Oh Su-a. Oh Su-a scolded him, saying, "Come here. How did you manage to sneak in with that identification?" while grabbing his sideburns. Pulling him into a corner, she warned, "I can tolerate you being a transfer student, but be careful. If I catch you again, it'll be straight to the counselor's office."
Jeong Hae-seong replied, "Hearing that is ridiculous. You haven't done anything right either. Therefore, you haven't done well either. Didn't you fight with me? Back then, you hit me mercilessly with a steel tray," he refuted. Flustered, Oh Su-a responded, "I did that to save you," and Jeong Hae-seong countered, "I never asked for your help. I acknowledge my fault. Let's acknowledge each other and move on amicably. It's the first day at a new school for me."
Later, Oh Su-a shared with her fellow teachers the story of her encounter with Jeong Hae-seong, mumbling, "Am I crazy to fall for him?" She added, "If you even try to mess with me, I won't leave you alone."
Meanwhile, Jeong Hae-seong, convinced it was the location where the gold bullion was hidden, secretly infiltrated the old building of Byeongmun High School. Upon discovering a suspicious area, he attempted to go down the stairs but encountered someone pointing a gun at him.
[Photo] Captured from the broadcast of 'Undercover High School.'